What kind of room has no windows or doors?

The riddle "what kind of room has no windows or doors" is very popular and the answer is a mushroom. Many riddles are plays on words or give properties of one item to another that has a similar sound or working.

Riddles held a place of distinction and took ingenuity to solve in the middle ages. The answers were not as transparent as some modern riddles. There were often contests between nobles and many traveling minstrels would use them to entertain their patrons for the evening. These riddles sometimes gave lessons on life and morality, while others were simply reflections on aspects of life at the time, such as cooking, farming and battle.