Recreational mathematics including puzzles to make and solve, tessellations, geometric puzzles, optical illusions, and curiosities.

Brain teasers, riddles, logic puzzles and problems, paradoxes, optical illusions, IQ tests and logical games.

Brain teasers, puzzles, riddles, games and optical illusions.

A collection of math, logic, and word puzzles.

Includes a huge collection of user submitted and rated brain teasers and riddles. It also has a message board and some unique multi-player games.

Paradoxes, puzzles, games, optical illusions, poetry, curious facts, and quotations.

A beautifully illustrated collection of puzzles, riddles, and paradoxes. Features a changing "unsolved puzzle" plus three years worth of previous puzzles.

A community based site with competitions, challenges, awards, a help centre, forums and games.

Challenge your mind with free online riddles/puzzles, logic games, brain teasers and view optical illusions.

Riddles, illusions, puzzles, and brain teasers.

Crosswords and other word puzzles and games, samples; monthly puzzle magazine; 800,000 word searchable list.

Have fun with games, puzzles, brainteasers and humor as you learn about logic and analysis.

Some real mind benders here.

Riddles, brainteasers, cryptograms, anagrams, and logic puzzles. Compete in eight new contests monthly.

Pascal Huybers presents information about a variety of different puzzles.

A collection of logic puzzles, riddles and brain teasers.

Recreations for active minds including games, puzzles, math, words, images, books, software and web guide.

Word puzzles, riddles, rebuses, brain teasers, mazes, cliparts and pictures.

Collection of puzzles including riddles, logic puzzles and sequential puzzles.