MagicManICT wrote:You can't seal a cave entrance from the inside to block people from using it outside. You have to block it outside to prevent people from using it. I've always liked building a brick wall section directly in front of the cave entrance if I don't want anyone accessing it and I don't need it.
The other question: water doesn't exist down there, only on L1 underground.
Thank you for the helpful answers.
Follow-up queery:
Has anyone found high q water on L1 underground? I want to know if I should waste the energy building a boat to sample the water.