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Geocaching 103: Puzzle Caches
by Carolyn K. director, Hoagies' Gifted Education Page
Puzzle caches, also called Mystery Caches, may be the greatest challenge and the most fun of geocaching. A puzzle cache might require you to solve a logic puzzle: Sudoku, word search, or number or word puzzle. But a puzzle cache might ask you to figure out what you're looking at and looking for... are the clues to solving the puzzle in the title, the description, or in the HTML code hidden inside the page? A puzzle cache might be a series of morphing pictures revealing the latitude and longitude, or revealing another step to follow to the solution. To their credit, many puzzles include a "geo-checker," a link to a website that checks your puzzle solution online before you spend hours searching in the wrong place.
The trickiest part of a puzzle cache is often getting started. One puzzle master suggests that most puzzle caches fall into specific categories...
Site puzzles are puzzles that require you be at the site to solve. Cache coordinates are often the parking coordinates for these caches, where the puzzle begins. You may be asked to observe or explore local geography, history, or more. You never know what a site puzzle will be like until you get there! Site puzzles are a great way to get started with puzzle caching.
Trivia puzzles are those puzzles where the numbers are represented by objects, lists, sports teams, presidents, dates, and any other kind of trivia you can think of. We found one puzzle cache based on the history of Pickles. I relished it! We did another that was based on the par of holes on a local golf course with the final located near the 19th hole; it really teed me off. But enough being punny...
Wordplay includes crosswords, anagrams, word search, acrostics, cryptograms (which are also covered below in Cryptography), and jumble puzzles. The cache might have you solve a word search puzzle, and use the remaining (uncircled) letters to determine the location of the cache. To make it a little more interesting, those remaining letters may be encoded!
Mathematics puzzles range from the simple to the sublime. Geo-arithmetic is easy enough: the sum of the fence posts minus the windows on the south face of the historic building equals the first missing digit, and so on. Projections, triangulation, and other math puzzles might be more complicated, especially without a few special tools. Check out FizzyCalc for some of the fancier calculations on these puzzles.
If you live near a University, math caches might be a little tougher. One of the puzzle caches "placed" on the Mathematics building at Penn State consists of actual questions from the American Regions Mathematics League (ARML) competition, not to be confused with the simpler "Freshman subjects" series located nearby.
Logic puzzles may involve solving a Sudoku puzzle, cause and effect, riddles, and clues. This category covers a multitude of sins, er, puzzle caches.
Cryptography is very popular among puzzle cachers. Even if it's not the point of the puzzle, the eventual results are often encoded just for an added solving "bonus." When your wordplay puzzle ends up with a jumble of letters, try solving it as Caesarian Shift (also know as ROT) or Cryptogram puzzle. Not into solving your own cryptograms? Don't despair; some of the tools below will try to solve them for you!
Crytography also includes other languages as codes. Morse code, Roman, Greek or Chinese numerals may all play a role in a puzzle cache. If your CO is a software engineer, look for ASCII or HEX or other computer encodings to be featured in the cache.
Steganography is the art or practice of concealing a message, image, or file within another message, image, or file. Steganography puzzles are the puzzles I love to admire, but often have no idea where to begin. Camouflage, pictures, meta-tags, source code, white text... the examples exceed my imagination.
Animated gifs (pictures) morph from one view to another... and may have the words or numbers of the lat/long hidden in the layers; GIF Explode is a tool to separate the layers to examine them carefully. Magic eye puzzles, where you have to stare and cross your eyes to see the results are tricky for some of us, especially with aging eyes. Magic Eye Viewer helps with these. But sometimes these puzzles simply require brute force: hours of decoding the pictures and figuring out what the results are trying to tell you.
Lateral thinking puzzles are those quirky, out-of-the box puzzles that have you use a tool in a way you wouldn't expect. Can you flex your brain to think like the Cache Owner (CO)?
Obfuscation. Just what it says... COs may misdirect, mislead, and provide you with all manners of gibberish, only to have the real answer hidden nearly in plain sight. Sometimes it really is as simple as it seems... and the rest is just a distraction!
Challenge caches aren't puzzles at all, but, classified as Mystery (Puzzle) caches, they will be among the hardest puzzle caches you solve. In a challenge cache, the actual cache location is usually right where the lat/long places it. However, in order to claim the cache "find," you must meet the requirements of the challenge. Challenges may be as simple as finding the rest of the CO's caches in a series, or as complicated as... well, more complicated than most cachers will ever accomplish.
Some of the most common challenges are...
Whenever you're looking for a lat/long in a Puzzle Cache, there are some "magic numbers" you should keep in mind. For example, there are 15 digits in a full lat/long... but in many areas, one of those digits is a 0, so the magic number of digits to look for in a puzzle might also be 14. And since the final location for a Puzzle Cache must (now) be located within 2 miles of the lat/long specified as a default, the first 3 digits of latitude and 4 digits of longitude will always be the same as the digits you are already given. So the "magic number" of digits you're looking for may be down to 10 (the last 5 digits each of lat/long), or even 6 (the last 3 digits each of lat/long). Whenever you're examining the text or graphic contained in a Puzzle Cache, look for a "magic number" of items, that could be somehow "translated" into digits for the lat/long.
And remember... numbers aren't always digits. One, Two, Three... sometimes digits are words!
What can the Cache Owner (CO) control in the Geocache page?
When you're reading a cache description, focus on those things the CO can change.
The CO can control everything inside the Cache Description section. Are there links to other content? Videos? Is there a picture, perhaps an animated gif that might contain more information? Move your cursor around the picture to see if there are "key tips" that might prove useful.
Are there hints hiding in the white space in the description? Highlight the whole Cache Description, and see if anything appears. Are there certain letters capitalized, especially letters that don't start a sentence? Collect those, and see if they're important.
When all else fails, lift the curtain and look...
Behind the scenes
The HTML source code of the cache page is sometimes involved in the puzzle. If you're not a programmer, don't let this scare you. HTML is just fancy English. To view the source code of a web page, click <Ctrl U> and the code should appear, regardless of your browser. The biggest problem looking at the HTML is finding the content added by the Cache Owner (CO) among the code provided by geocaching.com. The easiest way is to search for the words "cache description"... you'll be at the top of the HTML section you are looking for, the part the Cache Owner (CO) can control and edit. Once you've found the CO's HTML code, look for links (they start with http://) that aren't visible from the cache page, or other clues within the code. Spare links that aren't displayed on the page are often links to the solution, or at least another step in the puzzle. And be aware... <!-- Anything inside these markings is an HTML comment... and may be a clue. -->
Some COs use content that can't, for one reason or another, be deciphered on a smartphone or tablet. Your PC is your friend. Sometimes your browser matters. If you can't see anything about the included picture in Chrome, consider viewing it in Internet Explorer or Firefox. Or vice versa. It all depends on what the CO has available to create her content on. Sometimes being a Mac user is an advantage... particularly if the CO is a Mac user.
Ciphers and Codes
Puzzle cache owners seem to love to turn words into codes. And there are all sorts of codes out there, but the most common code used in Geocaching is the same code that you see in the "hint" section of each geocache description: a ROT shift or Caesarian Shift code. The "hint" section uses ROT 13, but you can use any number from 1 to 25 for the shift... and often, the CO will give you that number somewhere in the puzzle description. For example, you might solve a Word Search puzzle, and have some strange letters left over when you're done circling all the hidden words. Play with those spare letters in a Caesarian Shift solver (this one is from Rumkin, below), and you might find the missing information you're seeking!
Note: Since puzzle caches are time-intensive to create, and because in some regions unethical folks are signing up for a free account on Geocaching.com and then searching and destroying caches, many Cache Owners choose to make their puzzle caches Premium Members Only caches. This means that until you sign up as a Premium Member of Geocaching.com you may not see all of the puzzle caches in your area.
Instructional puzzle cache series...
Learn about puzzle caching by solving these puzzle cache instructional series, even if you don't live anywhere near the caches. If you're lucky enough to live or visit near the geocaches (both series are located in Florida) you can also make the finds, but each cache comes with a GeoChecker to confirm your puzzle solution from afar. Puzzle Solving 101 - Lesson 1: Strategy, the first of 10 steps in Puzzle Solving 101 and a great series to learn about puzzle caches (Fort Lauderdale, Florida), or Puzzle Shortcuts 1: Caesar Shift, the first of a series of 11 caches designed to help you learn how to solve a variety of puzzle caches (Cape Coral, Florida). Or visit the series north of Detroit, Michigan starting with Puzzle Solving 101 - Colors.
Creating your own puzzle cache can be as simple or as tricky as you'd like to make it. What's your favorite kind of puzzle? Sudoku? Word Search? Create your puzzle caches using the puzzles you know and love. Sudoku is easy... just put a little A, B, C, etc. under certain blank cells in a Sudoku puzzle; cachers will solve the Sudoku puzzle to learn the latitude (AB° CD.EFG) and longitude (HI° JK.LMN) of your final location. But I'm at N 40° latitude, you say? No problem... just don't put a B in your Sudoku puzzle. Cachers will (eventually) figure out that missing numbers must be zeros.
You're more of a alphabet kind of puzzler? Create a Word Search with words of your favorite topic, from Pickles to Marching Bands or anything else in the world. Be sure to leave some unused spots in your Word Search, and use those spaces to add the answer to your puzzle... in words. When they've solved the puzzles, the remaining letters equal the location of the cache: North forty degrees fifty nine point one two three, West... you get the idea. If this sounds too easy, use a cipher (above) to code the solution before you add those letters to the puzzle.
If you'd like to create a Gadget Cache, be sure to visit WVTim's
Gadgetcaches Channel on YouTube. Tim not only shows off some of
his creative caches, but shows how to create caches like his for your own
Here are some of the most commonly used puzzle solving tools. Find code breakers, geography calculators, and blogs on puzzle solving, as well as a tool to decipher animated gif files. And if you have tools that help you, be sure to share them with us at firstname.lastname@example.org!
Updated April 02, 2019