Welcome to Geocaching - Solving puzzles’s documentation!

Basics

  • Unless otherwise specified, the cache should lie within 2 miles (3,2 km) of the dummy coordinates.
  • There must be a distance of 161 meters between physical GC waypoints (including cache locations)

Here are the items you should check within the GC page:

  • Description
  • Cache name
  • Main body of the page
  • Source code of the page
  • Owner
  • Related web page (top of page, just above dummy coordinates)
  • Dummy coords, check on Google Maps and StreetView (this could give a hint)
  • Waypoints
  • Background image (especially if hosted on a different website than geocaching.com or amazon)
  • Attributes (they can give hints but also be converted to numbers)
  • Photo gallery
  • Bookmark Lists
  • Trackables
  • GC Number (can be used as cipher key, converted to decimal)

Search for :

  • Google about keywords
  • Search for images and their alt-text
  • Search for any coordinates and numbers
  • Geohash
  • Search for items in group of 10, 14 or 15
  • Check within geochecker

Simple text puzzles

This lists simple text puzzles

Look for:

  • First letter of words (or nth letter)

  • First word of each sentence

  • Different letters (italic, different font, colors, …). This could be a Bacon cipher

  • Look into the source code for information (CTRL-U in most browsers)

    • search for background image
    • search for HTML tag <UserSuppliedContent>, this is where the description begins
    • search for strange characters and tags, hidden content
    • search for hyperlinks and alt-text

Letter puzzles

  • Mazes: path goes through numbers
  • Word searches : left-over letters are the solution
  • Cryptograms Apply a letter substitution. Take into account the letter frequencies, if possible. Letters frequencies English: ETAORISHD
  • Crosswords
  • Anagrams
  • Sudoku and variations
  • KenKen
  • Kakuro
  • Nonograms - Griddlers - Picross
  • Stereograms

Coordinates

Systems

Notations

Tranformations

  • Projections (distance and bearing)
  • Centroid (center of gravity)
  • Lines Middle of a line Intersection of lines
  • Circles and lines
  • Circles intersections (3 circles to get a unique waypoint)
  • Antipodes
  • Compute coordinates on great circles
    • Vicenty formulae
    • FizzyCalc

Units of length

  • Imperial inches, feet, yards, miles, chain, furlong, league, fathom, cable, nautical mile
  • Metric Also used in UTM system
  • Ancient units
    • Egypte: finger, palm, hand, fist, span, cubit, rod, iteru
    • Rome: foot (pes), cubit, step, pace, stadium, mile, league
  • Unusual units smoot, sheppey, parsec, …

Angular units

  • Degress: circle=360°
  • Radians (conversion to degress: *180/pi)
  • Angular mil: milliradian = 1/6283
  • American mil: 1/6400
  • Turns: 360°, centiturns, milliturns
  • Gradians: circle=400 grads
  • Pechus, hexacontades, signs, angle hours, points

Substitution and Index

Substitution

Anything can be replaced by numbers.

  • Look for group of 6/10/14/15 digits. If you have a large amount of items, you are looking for a text message, not numbers.
  • Alphabet
  • Atom numbers of elements
  • Change keyboard layouts (including Dvorak)
  • Use a different font (Symbols, WingDings, …)
  • Substitute arbitrarly and go through a cryptogram

Codes

Simple Ciphers

Advanced Ciphers

Ciphers Identification

Cipher with letters only Ciphers with letters only

Indices and tables