Underground

Words referring to the area under the ground, and to holes in the ground.

• What words refer to the area under the surface of the earth?
  underground below ground subterranean abyss bedrock core mantle stratum subsoil
• What words refer to natural holes in the ground?
  hole cave cavern grotto opening crack depression hollow cavity channel chasm cleft cranny crater crevasse crevice depression dip mud hole pit sinkhole mouth of a cave
• What words refer to man-made holes in the ground?
  conduit culvert ditch foxhole mine pit pothole rut subway shaft trench trough tunnel well
• What words refer to a hole made by an animal?
  burrow den foxhole lair
• What words refer to water under the ground?
  aquifer underground river