An openpit quarry sunk below ground level. Access is gained by stairs, ladders, or mechanical hoists, and material is conveyed from the quarry by inclined tracks, trucks, derricks, or cableway hoists. These pits may reach depths of several hundred feet. A drainage scheme will in most cases be necessary, as the pit will form a natural sump for both surface and subsoil water. This type of quarry is often used for gravel or soft rock that can be extracted by some form of digging.