If you're really curious about what goes on down there, you should read the works of Nick Johnson, author of the "Big Dead Place" blog and a subsequent book.<p><a href="http://feralhouse.com/big-dead-place/" rel="nofollow">http://feralhouse.com/big-dead-place/</a><p>The blog is off line (might be on archive.org), and Johnson sadly took his own life in 2012.<p><a href="http://feralhouse.com/nick-johnson-rip/" rel="nofollow">http://feralhouse.com/nick-johnson-rip/</a>