Brain

• Brain Boosters ...lateral thinking, logic etc
• Brain Fun ...Brain Teasers, Puzzles, Games and More
• Brain Juice...food-colouring-and-preservative-free mental stimulation!
• Brain Teasers
• Brain Teasers
• Brain Teasers
• Brain Teasers
• Brain Teasers and Games with a Neuroscience Angle ...A selection of the 50 Brain Teasers that people have enjoyed
• BrainBashers...puzzles
• BrainFood
• Braingle
• Brain Metrix
• BrainQuest
• Brainwave...collect 10 bulbs..
• Buoyancy Brainteasers
• Exercise Your Brain! ...Games and activities that offer great mental exercise
• FunBrain
• Gamequarium Brain Teasers
• Games for the Brain
• Mathematical Brain Teasers and Puzzles
• Feb 18 -ProProfs ...Play brain games, free puzzle games and create your own game!
• Sharp Brains ...The best science-based information and guidance for Brain Health and Fitness
• 24 Quick Brainteasers ...A set of 24 brainteasers that are quick and each have a creative answer

    Crossword Puzzles

• Feb 18 -The Crossword Network ...Free Crosswords - Online Crossword Compiler

    Games

• Internet Scrabble Club
• Prognosticate ...news game
• Scrabble
• SCRABBLE + Logology
• Scrabble Help
• Scrabble Rack
• Trivial Pursuit Online

Illusions

• Akiyoshi's Illusions
• BrainDen Optical illusions ...Several types of optical illusions sorted into detailed categories
• Exploratorium Illusions
• Eye Tricks ...optical illusions
• llusion Sciences ...A new illusion every week
• Mighty Optical Illusions
• Optical Illusions
• Optical Illusions
• Optical Illusions & Visual Phenomena
• Planet Perplex Illusions
• Sandlot Science Optical Illusions

IQ Tests

• High IQ Society
• IQ League ...Try the 60 second IQ test
• IQ Test
• IQ Test
• IQ Tests ...An IQ in the range of 90 to 110 is considered average
• IQ Test
• IQ Testing Lab
• Majon's Online IQ Test
• Puzz.com ...IQ tests, puzzles, games, trivia etc

Logic & Math Puzzles

• Conceptis Puzzles ...The home of logic puzzles
• Fun Logic Puzzles ...Some simple recreational logic puzzles. See if you can solve them!
• Interactive Mathematics Miscellany and Puzzles
• Logic Puzzles ...require no particular knowledge and can be solved using logic alone
• Math Goodies Word Searches
• Mathematical Puzzles ...for the mathematically adept
• Maths Puzzle
• Nick's Mathematical Puzzles
• Problem Corner
• Project Euler ...A series of challenging mathematical/computer programming problems
• Pythagorean Puzzle
• The Hardest Logic Puzzle Ever ...see for yourself!
• Who keeps the Fish?
• 100 Interesting Mathematical Problems, Exercises, Puzzles, and Diversions

Mazes

• Caerdroia - Journal of Mazes and Labyrinths
• Click Mazes
• Great Mazes
• Jo Edkins' Maze Page
• Logic Mazes
• The Maze
• World Maze Database

Mensa

• Mensa
• Mensa Australia
• Mensa Canada
• Mensa Puzzles
• Mensa Workout

Miscellaneous Sites

• Aenigmatica...a gymnasium for your Brain
• Auto Puzzles
• BrainsBreaker Online Jigsaws
• Card Trick Central
• Codebreaking and Secret Weapons in WWII
• Codes and Ciphers
• Cryptographs
• DaVinci Code Quest
• Decipher ...A series of fourteen cryptograms
• Decoding Nazi Secrets
• eCardTricks
• Edgar Allan Poe Cryptographic Challenge
• Encyclopedia of Integer Sequences
• Filmwise Invisibles
• Jigsawland
• JigZone
• Mentat Wiki ...A collaborative environment for exploring ways to become a better thinker
• myRebus ...Magically makes a rebus of anything you type
• Pharaoh's Pump
• Riddle Nut
• Riddles
• Secrets of the Mind
• The Great Enigma Challenge
• The New RSA Factoring Challenge
• The Official Mega Society Home Page
• The Problem Site
• TheJigsawPuzzles ...Ever-growing collection of free online jigsaw puzzles

Puzzle Pages

• A1 Puzzles and Crosswords...Interactive Crosswords, Puzzles
• AIMS Puzzle Corner
• Archimedes Laboratory...puzzles
• Bambam's Puzzlesite
• Bits & Pieces Puzzle Arcade
• Break the Code
• Classic Puzzles
• Clifford Pickover's Page...puzzles within
• Combination Lock ...puzzle
• Conundrum of the Month
• CR Puzzles
• Cricklers...wordpuzzles
• Eluzions Puzzles ...Wide variety of mental challenges
• Erich's Puzzle Palace
• Feb 18 -FreeInternetPuzzle ...Kill some time with games that are intellectually stimulating
• Funhits...puzzles etc
• Games Magazine ...Consumer magazine featuring a wide variety of verbal and visual puzzles, brainteasers, trivia quizzes, etc
• Games & Puzzles
• How Puzzling...
• How to Make Puzzles
• Inside Japans Puzzle Palace
• Jason Zahn Game Show
• Jed's List of Situation Puzzles
• Ken's Puzzle of the Week
• Labyrinths
• Lateral Puzzles
• Lateral Thinking Puzzles
• Lesson Corner Puzzle Makers ...For Teachers and Homeschoolers who want to make engaging handouts for vocabulary building exercises
• Lovatt's Online Puzzles...crosswords etc
• Matthew's World of 20KB Puzzle Programs
• Microsoft Puzzle Collection
• Mind Breakers
• National Puzzlers' League
• Nature Puzzles & Fun
• Overture Facile ...online puzzle
• Pennypress Dell Magazines...Free puzzles and more every day
• Period.com Puzzles
• Ponder This
• Puzzability Puzzles
• Puzzle Choice
• Puzzle Connection
• Puzzle Crypt
• Puzzle Factory
• Puzzle Games ...Play Online Puzzle Games, Jigsaw Puzzles Games, Sudoku Puzzle Games and Popular Games in Your Free Time!
• Puzzle Maker ...Create and print customized word search, crossword and math puzzles
• Puzzle Mania
• Puzzle of the Month
• Puzzle Pirates
• Puzzle Playground
• Puzzle Pointers
• Puzzle World
• Puzzler
• Puzzles for the Avid Consumer
• Puzzles
• Puzzles
• Puzzletron
• Puzzling Adventures: Sir Birnie's Will ...How a 14-year-old solved the mystery of an apparently miserly grandfather
• Sam Loyd's Cyclopedia of 5000 Puzzles
• Sam Loyd's Fifteen Puzzle
• Sound Puzzles
• The Cyclopedia of Puzzles
• The Einstein Puzzle
• The Grey Labyrinth
• The Puzzle Club
• The Puzzle Depot
• The Puzzle Society ...Games to maintain your brain
• The Puzzler
• The Puzzling World of Barry R. Clarke
• The rec.puzzles Archive
• The Set Daily Puzzle ...And other various puzzles
• The Ultimate Puzzle Site
• thinks.com...for people with active minds
• Three Puzzles from Martin Gardner ...Here's a taste of the kinds of puzzles he was famous for bringing to the world
• Tim's World of Puzzles
• Web Puzzler
• Wei-Hwa's Puzzle Challenges
• What is it?...photo puzzles
• Wordly-Wise...word puzzles
• World Puzzle Championship History
• 123 Puzzle Games...freeware
• 2000 World Puzzle Championships Selections

Quizzes & Tests

• Art History Quiz
• Barbarian's Online Test Page
• Cool Quiz
• Free Quizzes
• Games, Puzzles, Quizzes, Tests
• Geometry Quizzes
• JetPunk ...Visit JetPunk for the world's best quizzes, with new quizzes released every day
• Jung Typology Test
• Personality Quiz
• Personality Test Center
• Psychology Tests
• Quiz Factor ...Fun, fascinating and free quiz site where you can test your knowledge and challenge your friends
• Quiz Farm
• Quiz Hub
• Quiz
• Quizify ...Quizify is a flashcard-style program to help with studying
• Quizilla
• Quizzes for All Ages
• The AHA! Science Quiz
• The Daily Quizshow
• The Google Maps Quiz
• UN Quizzes
• Wait Wait-Don't Tell Me!...quizzes
• World Quiz League
• World's Smallest Political Quiz
• 916 Test...good luck!

Rebus Puzzles

• Puzzle Soup
• Rebus Puzzles ...word picture puzzles
• Rebus Puzzle Brainteasers ...word picture puzzles

Rubik

• How to Solve a Rubik's Cube ...If you read this method, that's it, you will never have solved it thanks to your wits
• How to Solve the Rubik's Cube ...Make one twist and then make another
• Rubik Online
• Rubik's Cube
• Rubik’s Cube solutions
• Solving Rubiks Cube
• Solving Rubik's Cube for Speed ...This is a tutorial for a method of solving Rubik's Cube

Sudoku

• Pi Day Sudoku Puzzle ... Fill in the grid so that each row, column, and jigsaw region contains 1-9 exactly once and ? three times
• Fiendish Sudoku

Trivia

• Absolute Trivia
• All Trivia Game
• Cascoly Online Trivia Games
• Fibonacci Flim Flam
• Fibonacci Numbers and the Golden Section
• Fun Trivia
• Harper's Index
• Highest, Lowest, Deepest
• Historical Trivia
• Trivia
• Trivia Bytes
• Trivia Cafe
• Trivia Challenge
• Trivia Page
• Trivia Web
• Useless Knowledge
• 80's Trivia

Wooden Puzzles

• Mr Puzzle Australia
• MGC Wooden Jigsaw Puzzles ...custom made

Word Puzzles

• Crickler...puzzle
• Fake Out!
• Free Word Search Puzzles
• John's Word Search Puzzles
• Metacrostics...from Arthur Bloch
• Numbers & Word Puzzles
• Apr 06 -Online Word Search ...Online Word Search is a website where you can play word find games
• The Enigma Device
• Think Puzzles
• Todays Encrypted Quote & Contest
• Word Game of the Day
• Word Puzzle Contests
• WordWays Puzzler ...Can you fill in the blanks with no hints?