Quicksand
From WikiRaider
Quicksand can be found only in Tomb Raider III, in Nevada.
It is a dangerous trap since it is hard to spot. The quicksand looks like soil, so it blends in very good. The only thing that can give it away is the mild water-like movement. When Lara steps in quicksand, she will start to rapidly sink in. Lara can move through the quicksand, but as soon as her head goes under it, she cannot surface, even if there is a climbable ledge in front. If she can make it in time to safe ground, she can pull herself up.
