A thick marsh of quicksand-like mud sucks everyone in who tries to walk through it. Boats are necessary but get stuck quickly on the sallow ground. They must be pushed off the ground with paddles or sticks. If anybody tries to jump out and push by hand they will soon learn what vicious or venomous critters hide in the swamp. Additionally, thick swarms of blood-sucking insects emerge from the water as soon as it is disturbed.

NOTE: I used this map originally in a modern setting. That's why there is an overgrown tank in the central island. It's the only modern asset and you can easily select and delete it.