24 Amazing, Homemade Dungeons and Dragons Maps

The creativity really amazes me. For example,

Mollusca Tullie (to the East, in the Unfathomed Fens) is actually a small settlement of nomadic halflings—built on the back of a giant snail. They defend the snail with their mastiff cavalry and in exchange, the snail provides its shell as a shelter.

Are there online communities where this sort of thing is common?