A city in the sky sitting on a giant kite. No, thousands of small kites! No, a small number of kites that move under peoples' feet!
A land of no land, just falling.
A village built in the eyebrows of a narcoleptic giant.
The forest of really heavy mushrooms, with the problem of spontaneously collapsing trees.
A crystal house that projects shadow puppets from direct sunlight. Maybe just a world inhabited by shadow puppets.
Opposite land's opposite land or "same world" where everything is opposite to opposite land but in a slightly different way. eg. Gravity works in the opposite direction, but everything's upside-down. Cats chase dogs, but they run backwards. Everything's on fire, but fire is cold. Scaly birds swim underwater and feathered fish fly. I could go on.
Ninja village that's seemingly uninhabited.
Point-and-click planet, where flocks of cursors keep telling you what to do.
Puppet forest. A place where the inhabitants are puppets hanging from trees, or more accurately, smart ventriloquist trees with puppets. Maybe with jack-in-the-box seeds.
[del]Land of the dead.[/del] (no, too clichéd)
Mirror world that's impossible to enter because mirror-you is in the way. Also, vampires don't exist.
Backwards world, where you have to disassemble useful items and return their components back to their original owners.