The website called BrainDen shows riddles, puzzles, paradoxes, optical illusions, and offers games for the brain. It also offers links for IQ tests and puzzles, along with a forum for individuals to discuss and offer their insight, about those brain teasers.
After reading some of the paradoxes and looking at the optical illusions, BrainDen looks very appealing as a great website for brain exercise, and a fun way to explore 'logic's (sometimes) illogical scope' -- if you will.
The forum that BrainDen offers for individuals to express insight, and discuss the irony of paradoxes, along with the fun things offered on the site -- is definitely a plus.
Perhaps, you can check out some of the engaging challenges and fun stuff, for a little brain teasing and stimulation.
Paradoxes