Some of these are amazing. The big one in the middle of the town looks like it was drilled by some giant drill the side are so smooth and even. The little one in the beginning is is Leadville, Colorado caught my eye, becasue by buddy and I spent a day in Leadville jetting his motorcycle for Pikes Peak. Its the highest elevation city in the USA, over 11,000 feet. We found a mining road at about 12,500 and spent the day jetting the bike for high elevation. Some of these pictures are pretty awesome.
http://news.yahoo.com/photos/massive-si ... 11853.html