0kclsBest Answer 8 years ago ReplyUpvoteWell, there are several different sizes of geocache, ranging from micro, to large. Micro is about the size of a C02 cartridge for a bike tire, and usually contains a small rolled up piece of paper to write your username on. The large kind is usually a military ammo box and it contains a log book and several small trinkets. Sometimes there is a prize for the first to find. There is often toys, pencil sharpeners, everything! I once found a laminated 4 leaf clover. You go to the geocache, and you take something, leave something, and sign the logbook. Usually this is referred to as TNLNSL. It is a fun thing to do with the family, and is better then sitting on the couch all day! Good Luck!