Introduction: Treasure Hunt for Adults (companion to Arduino Treasure Hunt Box)

I have always liked movies like National Treasure and the like. Ones that has a team of people that are running all over trying to solve some riddle or a string of riddles to, get the gold, get the girl, save the world, become instantly rich,etc.

I have three adult children and getting them gifts for Christmas or birthdays has always been a challenge. The average gift holds their interest for only a short time and I wanted to make something that they would remember and talk about with their children. So I created a treasure hunt that wound its way around our town placing clues and keys in libraries, police stations, school play grounds, friendly businesses, parks, memorials and anyplace else that catches my fertile imagination. The first version was a horrible failure. The kids were good sports about my mistakes and we muddled through. Version two was much better as I got my pride out of the way and asked for help. Version three backslid some as I started using Arduinos to make the final prize more flashy. The fourth version was a total success. This is an instructable based on the fourth version that is shaped to use the Arduino treasure hunt box. I have to tell you up front that the average hunt that I create takes me about a month or two to create on paper and then another month to get everything set and placed and people to help etc.This instructable is how I created my treasure hunts. Of course there is no one right way. This instructable is a companion to my other instructable of an Arduino treasure hunt box.

Some of my other instructables that will help in the making of a treasure hunt

Step 1: Set Out Your Route...

Because the Arduino treasure hunt box has five objects and one code to be discovered to make it work, I make up my treasure hunts in six individual hunts. The box has: a ring of power which is used to power up "the box", five puzzle pieces that act as keys, and a four digit code to open the box after all the keys are discovered and installed. The first hunt has several steps that need to be solved to gain the ring of power. The second, third, fourth, and fifth hunts each have a task to complete to obtain the keys, and then there is a final riddle that when solved gives a 4 digit code.

Step one: set your route. Where do you want your team to go. I created my treasure hunt for collage aged adults. So I started at 8:30 AM at a bagel shop in town where breakfast could be had and the rules discussed. From there they went to the town square to get a clue to the next location. That clue led them to the police department to recover the ring of power from a cop with a sense of humor and fun. After some meet and greet he gave them the ring. This directed them to the box. The ring of power activated the box and the box delivered the next clue to the second task.

The team went to the vets memorial to decode a message from a plaque, that lead them to a stash of tools in a unused paint can bought for a couple of bucks from home depot. Inside the can was a clue, a compass, a UV flashlight, and a printed code key. The clue took them on a compass course to find the first key and a note stashed under a flower pot.

With the first key in hand the team was directed back to the box. The ring of power was waved over the activation spot and the first key was inserted. The box them gave them a clue to the third task. This happens for each of the remaining 3 puzzle pieces. The key here is that there is 4 or 5 step task and then back to the box with key in hand.

Once all the keys have been awarded and inserted into the box the program looks for a 4 digit code. A riddle of some sort is usually how I get this done but we will get into this more later.

Step 2: Route of Treasure Hunt...

Now that you have a list of places that you are going to go you need to decide how you will move the team from place to place. Here is an example list of places.

Start - Starbucks

statue in town square


high school

hardware store

police or fire department

vets memorial



fair grounds

city pool

city park

Final clue - news stand

Step 3: Types of Tasks...

To move the team from place to place. I use a task to get them the next clue. A task can be anything from searching a place for something, solving a riddle, breaking a code or asking a person for something. Below is a list of the types of tasks that I have used so far successfully on several of my hunts.

1) Map and compass course

2) Gps location finding

3) QR codes for smart phones

4) Riddles

5) Codes

6) Ottendorph cyphers

7) Book cyphers

8) Transparencies over library books

9) UV Light and pen

10) Willing helpers

Each of these is discussed in the following pages

Step 4: Map and Compass Course...

Being a boy scout for ten years I got pretty good at map and compass. Our scout master was an old Korean war veteran. Every week we would do a little hike, 2 or three miles and he had set out way points for us to follow as we hiked. In looking back this must have taken an incredible amount of work on his part to have all this pre-prepared for us. (Thanks Mr Rose) So in his honor here is a crash course in map and compass.

The face of the compass is divided into 360 degrees starting from north and proceeding clockwise around to east then south, then west, then north again. Most people know this part. Due north can be either 360 degrees or 000 degrees both are correct. Due east is 090 degrees, south is 180 degrees, west is 270 degrees and back to north. In between each primary direction are sub divisions. Between north and east is oddly north east. Between south and east is ...yep south east. Those are easy ones. In the pirate and ship movies you will hear the captain say something like, "come left to south south west." This means half way between south and south west is the subdivision south south west. The one half way between west and south west is of course west south west.

If you were to look at the outer ring of the compass you would see the degree marks. There are 22 1/2 degrees between each subdivision. ( north, north northeast, northeast, east northeast, east, etc ) If you have a good compass you will have two rings one inside the other. One ring is numbered clockwise, the other is counter clockwise. Every 5 degrees you have hash mark. Every 10 degrees is numbered.

There are piles of different kinds of compasses out there for various kinds of work. I use one of two different kinds for treasure hunts.

1) Lensatic compass

2) Map compass

The lensatic compass is used for walking. The compass is opened and sighted down the face of it through the cap. A distant land mark is chosen and the team walks in that direction.

The map compass is used to make measurements on a map, and align the map to north.

By far I use the lensatic compass for the treasure hunts even though it is somewhat more difficut to use.Once the team gets the hang of the compass then it is a matter of sighting and walking.

To actually learn how to use one of the lensatic compasses go here and read the whole thing. Then buy one at Walmart or your local sporting goods store and walk around some and play with it

Step 5: More About Map and Compass Course...

Now that you know the type of compass that I use here is how I have successfully set up my map and compass courses in the past. Pick a fairly large area like a school grounds, the fair grounds or my favorite is a massive cemetery. This gives you room to move the team around and room for them to make an error and that error to matter.

Why would you need that error to matter you ask? Excellent question.

Here's why. If you send a team off looking for a target on bearing 180 degrees for ten steps, and then send a second team off on bearing 200 degrees for ten steps. The two teams will be standing more or less right beside each other. However if you do the same bearings and send them off say 100 yards then they get farther apart the farther out they travel. If the target is to find a 1/2 diameter black marble in the grass, that error would make a difference. So for the sake of making it more challenging a larger area is better.

Still not sure why that would be an error? When i do my map and compass course I give the first bearing say 090 degrees. Then when they make it to the first way point, there is a math problem that gives them the next heading. If they mess up the math problem then they are off in the wrong direction. Evil yes I know but challenge is what makes an adventure worth doing. Besides short of making a ban on all cell phones, everything that they need to solve the most difficult math problem is at the fingertips with one smart phone.

So when using a map and compass course you will need a starting point and an ending point. The part in the middle is the running around/solving riddle part.

Give the starting point to the team along with a direction and a distance. When they set off in that direction they will need a destination. ( a tree, a rock, a 1/2 inch black marble placed in the grass) If the destination is visible from the starting point they won't bother with the compass and will go directly to it, so you may have to be vague about the destination so they have to work for it some.( see first picture for example )

Once they get there you can either give them the bearing directly or make them work for it some.

Since I use this as a task i usually combine more than one thing to make the compass course have more depth.

Step 6: Gps Location Finding...

GPS can be very simple or very complex depending how you set it up. Here are the general rules on how GPS works. The earth is divided in to north and south hemispheres by the equator. It is also divided into east and west hemispheres by the international date line that passes from north pole to south pole through the Royal Observatory Greenwich England.Thus the term Greenwich mean time or the place where the time zones are based on. Also known as Zulu time or UTC.(coordinated universal time)

This matters in GPS because the numbers of GPS start (00.000000, 00.000000) at a point in the ocean where the international date line and the equator meet. This point is in the middle of the ocean just south of Ghana in Africa.

This is the reference point for the rest of the planet. We will call this the zero point. From the zero point the earth is separated in latitude (vertical lines from pole to pole) and longitude (horizontal rings that circle the earth parallel to the equator above and below it) From the zero point any lattitude that is west of this point is a positive number up to 180.000000. Any lattitude east of this number is a negative number up to -180.000000.

By the way 180.000000 and -180.000000 are the same place on the exact opposite side of the world from the 00.000000, The only difference is which way you traveled from the starting point. 180.000000 means that you traveled east to the opposite side of the world. -180.000000 means you traveled west to the opposite side of the world

Any longitude north of this number is a positive number up to 90.000000 and any longitude south of this is a negative number up to -90.000000. This acts somewhat different since the rings parallel the equator when you hit 90.000000 going north you are at the top of the world and are then going down the other side so the numbers then decrease from there. The same goes for the south pole. When you hit -90.000000 you are at the bottom of the world and the numbers then reverse back as you come up the other side.

OK now that we know how the earth is divided up what do those other number on the right side of the decimal point mean? Good question and perfectly timed

GPS locations can be written two ways

38.5816° North, 121.4944° West which is the location of Sacramento,CA

or the way google maps does it 38.581600, -121.494400 which is the same location.

Notice the minus sign in front of the second series of numbers? That tells Google maps that you are WEST of the prime meridian or international date line. If you leave the minus sign out that tell Google maps that you are EAST of the Prime Meridian and you end up somewhere in the Yellow Sea between China and North Korea. The same works for the first series of numbers. if you put a minus sign in front of the 38 then you end up in the ocean halfway between Chile and New Zealand.

So quick recap positive numbers are above the equator for longitude, and east of the Prime Meridian for latitude. Negative numbers are south of the equator for longitude, and west of the Prime Meridian.

Step 7: How to Find a GPS Location of Something...

Now that you have a feeling for what GPS is how do you find the GPS location of something. There are two ways to do this. Go there and take a reading with a GPS app on your phone or goto Google maps.

If you are using Google maps there is a neat feature they have. In the search bar enter the name of something that you are looking to mark. Say Al's burgers in Seattle, Washington. (made that up) Google maps will take you there in map mode. If you then click on the point where you want a GPS location for, a small bar will appear at the bottom of the screen with the GPS numbers in it. Easy squeezy.

NOTE: GPS is only accurate to about 2 meters (6 feet) if you have perfect reception of the satellites. This means that where you placed the GPS dot on the map can move around a 12 foot circle so when you are building your treasure hunts plan accordingly. This will get them very close but still they need a target to find when they get there.

Step 8: QR Codes for Smart Phones...

This is a recent find for me and I am loving the ease that you can make up a treasure hunt with these.

The picture is and example of a QR code. They look familiar because they are on all kinds of packaging. You scan your soda with your smart phone and it takes you to their website where they have more things for sale. The QR codes can be programmed to make your smart phone do all kinds of things.

You may need to download an app to enable your phone to scan these. I use QR Droid Private from the play store. Most apple phones are already able to scan. If not find an app that will enable your phone.

The Internet is full of places that you can go to make free QR codes. is where I go to make mine. This is a free site that will allow you to make your own codes.On the left side of the page are the various types of codes that you make. Primarily I use three of them; website URL, google maps location, and plain text.

-The website QR code tells your phone to goto a certain website.
-The Google maps location allows you to enter a GPS location. It encodes it onto the QR code. When scanned it will open Google maps on your phone and then take you to the specified location. Very cool.
-The plain text code just translates the code into plain text that you can read without having to goto a website.

Because I have web programming ability I have programmed a web page to have pictures, text , and video to make an entire clue. But I have also used it to point to pictures on the web that act as a clue. If you can find it on the web then you can point to it with a QR code. Just goto the page that you are looking to point to, copy the entire address in the address bar and paste it into the QR Code Generator and poof it is made in seconds. Click the down load QR code and it saves it to your computer in the downloads section. Easy squezin squeezy.

Note: if you are pointing to a page on the web that you have to enter a user name and password to get to, when scanned the page will take you to the sign in screen and no farther.

Here is a twist that I have used. I create false leads for the team to go down if they make an error on solving a clue. They go down the path a few steps and then hit a dead end. You need to tell the team in advance that if they reach a dead end then they have to go back and resolve the clue that sent them down the path. Not being a devout religious type I was shown this by a friend. Makes for a great dead end declaration. Bible verse Book of Job 38:11 - 'This far you may come and no farther; here is where your proud waves halt!' Made me smile the first time I placed it and a team ran into it.

Step 9: Riddles...

This may sound pretty straight forward. Everyone has done riddles when in grade school. That is what makes it fun. I make up my riddles to give me numbers. Here is an example

Take the last 3 numbers of the license plate of the car that you are driving, add to it the freeway that passes north south through this town, subtract the number of the ages of the team added together minus 12, multiply by the number of graves stones in row 23 of the main street cemetery, add the year that Mr Jack Fairbairn died, plus the number of nails in a floor board in the hardware store In the front door third from the west wall. This number will be the code that you need to enter into a four digit combination lock on locker 46 at the high school to get your next clue.

As you can see the team is running to several different places to get the numbers that they need to finish the task. Smiles all around, especially for me.

Step 10: Codes...

Codes can be as complex as you want to make them. Here are some examples. Google "treasure hunt codes" and you will have more than you will ever need for codes.

A fast code to use is in Microsoft Word. Open a word document and type what you would like to encode. Select all the text and change it to wingdings. Poof instant coded message. Remember to increase the size of the font so that the team can see clearly what the symbol is when decoding. Also remember that each letter has to be decoded. Having to decode an entire page of text will get somewhat tedious and boring so remember what you code has to be decoded. Easy breezy lemon squeezy.

Step 11: Ottendorf Cyphers...

A what you say? An Ottendorf cypher. This is a cypher code that uses a fixed piece of text that is readily available to anyone and then it pick and chooses letters from that text by describing the location of each letter with a series of numbers.

Lets say that you have a plaque at a historical location (see picture)

You want to leave a message using this piece of text. To do so you encode like so


first number is the line of text from the top down

second number is the word on that line from left to right

third number is the letter of the word from left to right.

so in this example it would be the second line down, second word in, first letter which is R

your code will be a string of three digit number making up a word.



Note: Have more than one person decode this for you to make sure that your code doesn't have a typo. I have messed this up more than once and it proves to be a major pain. Even if you are very careful a second of inattention will move you one place left or right which will ruin that letter. Test it, test it, test it!

Step 12: Book Cypher...

A book cypher is similar to a Ottendorf cypher with a few additions.


First number is page of book

Second number is line on page

Third number is word on that line

Fourth number is letter of that word

This gives you a little more room to make a message. You can also make finding the book a clue in itself. I find that the reference section of the local library works well. Why the reference section you ask well that's because the books in the reference section are not allowed to leave the library so you know that they will always be there when you plan out your treasure hunt. If you need help ask your local librarian, they will be more than glad to help you get others into their library.

Step 13: Transparencies Over Library Books

I found this one on a total fluke. I was watching one of my kids' teacher correct a series of tests. She had a clear transparency that she had circled all the right answers. When the transparency was laid over the test she could see at a glance the correct answers. I though about that for a time and took the idea to my local library and found a large print book. I bought a pack of transparencies for a laser printer at office depot and laid one over a random book page. Using a fine tip sharpie marker I drew the page number and other lines that were on the page to align the clear sheet to the page in the book. Then I started on the top of the page and circled letters in order that spelled out the next clue. When I was looking for a letter that wasn't on the page like z or Q I would just write it on the edge of the column of text uncoded. This works well for locations and short clues. If you decide to use a finer type then you will have to be very precise about where the marks on the clear sheet are. I found that it works best if you use a binder clip at the top and bottom of the page and grip 20 or 30 pages along with the clear sheet to make the whole thing lays flat and does not get distorted from the clip.

Step 14: UV Flashlight and Pen

I found these on E Bay as a set.

These are fun to be able to write on things in plain sight and have the clue go hidden from the casual reader.

It works very simple, you use the pen to write on any surface. After it is dry it can't bee seen with out a very careful inspection. Even if you can detect that it is there you wont be able to read what is printed. When the light is shone on the written message it glows bright under the light. This effect varies with the surface written on. If you were to write on a blank piece of matte construction paper, a slight shine is left where the paint is located. However if you were to print a false clue on the paper with a printer and then use the pen to draw over the top of the false clue with the pen. That would be almost impossible to detect. I have used this as a false lead with wonderful effect. I printed a false clue on the sheet but also wrote the actual clue on the same page. The previous clue gave a hint like when looking on directions from others hold it to the light to see the truth. This can also be written on places and things to help direct the team. A neat thing that I have thought of but haven't tried is hints to very hard clues that use the light to move the team into the correct position. If the team isn't able to solve the clue then a "light hint" is given to move them over the hump.

Step 15: Willing Helpers...

I am usually somewhat reluctant to use helpers. Not that I can't find people to help me but the helpers are usually more interested in helping the team solve the riddle and moving on than just delivering the clue. Everyone wants to be seen as being a part of the solution. This means that the parts that you give your helpers needs to be designed to not give them an opportunity to spoil the next clue. They don't usually spoil it on purpose but it still happens. I have dropped envelopes with staff at the local hardware store and the team has to come in and directly ask a certain person for the clue with a code word or something of the like. I found a police officer with a sense of humor and fun (somewhat rare I might add) that acted as a moving clue that had to be tracked and then found to ask for the clue. Thankfully the town was small and his area was even smaller. He made it a fun cliché by sitting at the donut shop in plain sight. They ran all over looking for places they though he would be and in the end stumbled on him. Made me laugh at the look on their faces like duhh look at the donut shop.

One thing to remember about willing helpers. Life happens and sometimes they cancel at the worst possible time. Have a backup plan or person to take the place if life intervenes and buggers up the plan.

Step 16: Last But Not Least, Don't Over Complicate It.

Last words of painful experience. If it is so diabolically complicated then it will not be fun at all to run the course. It will be tedious and boring. Keep the pace moving. Better to have a pile of simple clues that keeps the team on the run than one really hard one that has everyone stumped and then the team has to call for clarification or explanation of what it is you are after. This acts like a fun sucker.

If you do codes, Ottendorf cyphers, book cyphers or any other code, have someone else proof read it by solving it. If you make a typo it can have disastrous results and send the whole event sideways and the only way to get back on track is the give the correct answer and point in the correct direction. Fun Sucker and makes you look kinda dumb.

If you use technology, test it, test it, test it then have someone else test it again. The fastest way to come to a screeching halt is to have a piece of tech fail and have no way around it. (This one really sucks the fun)

Finally make sure to send thank you notes to all the people that help you creating the treasure hunt. If you can include pictures of the team while they are on the hunt that is all the better. It will make it more likely that if you need their help in the future that they will jump at the chance to be part of it. Good Luck and happy hunting

A Machine Tech