Hi !

Here is another background fantasy sound atmosphere that I wanted to share with you.

This is the inside of a deep artificial tunnel, most likely a sewers. We can hear a lot of water dripping from several sources. A few gusts of the howling wind from time to time. Hatches opening and pouring out a thick and slimy content.
Mice and bats seem to be the main tenants of these corridors.
There is a constant rumble in the background that seems to be coming from deep depths of the earth, giving the impression of endless tunnels. The atmosphere is thick, wet and scary.

You can find this sound and loads more at: http://www.ogsoundfx.com