Links to play/explore

some interesting links:

Optical Illusion:
try this!

Some games:
requires some logic thinking. The first 15 levels are quite easy. But the subsequent few are hard. LINK

tests ur observation and logical-thinking skills (I've posted this link before).LINK

damn intelligent test, wasted my time thinking for the answer, but it's fun anyway. LINK

Some article to read:
about hell 1
about hell 2