The Cliffs Shaft Mine in Ishpeming, Michigan closed in 1969. Today, it is a national historical site, though I don't think that many people visit it. The buildings are abandoned and decaying inside, though the obelisk-like shaft houses, designed by George Washington Maher, still stand strong. It's a great place for photographers. I'm planning on returning in the spring when foot prints will not be so obvious. A few of these were taken by a friend of mine since he has no camera and I lent him my digital.