Question: how are the big holes in the ground created?

anon answered on 6 Nov 2018:

Hello,

Holes are made two main ways, either by quarrying and mining, or by drilling using drilling rigs (like oil rigs). I specialise in the drilling method.

Sometimes holes are created naturally, we call these sinkholes. They are created when water washes away soft rocks or dissolves them (like limestone) and then the surface falls into the hole.