Originally posted by M'Hael:

It's in towers that have stairs going down.

Some dvergr towers are dark, no yellow lanterns, and the side and tops of the towers have seekers. Usually means a set of steps inside leads down to an "infested mine".

Originally posted by M'Hael:

Sometimes there are mine openings in the side of hills and cliffs with a big set of stairs going up to it.

The big sets of stairs usually lead up to a very very very distinctive shape of mountain. It sort of looks (at least to me) like a face with three huge stone spikes spreading out backwards, kind of like the headdress of an american indian chief. This entire mountain spawns as one object. Once I learned what to look for I could spot the three huge backwards slanting spikes from different angles... I run around the mountain, and there'd be the stairs lead up.