The map ideas thread

If you come up with any good ideas, but don't want to use them, post them here for any potential mapmakers! Anybody that strolls in, feel free to use any idea you see in here.

Here's an idea of mine:
There are 5 different levels, which are each a long rectangular strip filled with enemies. At the end of each strip is a hard boss. There are 5 players, each with different skills. This is a hard map, and teamwork is essential. The players aren't heroes, but units. One player is the engineer. He can't attack, but he can speedbuild weak towers. One is the healer. He has the priest heal ability, dispell magic, and a weak attack. One is the attacker. He has a strong attack with weak armor, melee attack, and critical strike. One is the tank. He has lots of armor, a somewhat weak melee attack, and rain of fire. One is the spy. He has an average ranged attack, invisibility spell, and evasion. The enemies are difficult, and get harder every round. I stress, teamwork is needed. Each ability can come in handy.

TheBestofDaBest made something exactly like that, with more than 5 strips. He even said it was lacking details and advanced functions.

Sorry to burst your bubble... It's taken!