The Udachnaya Pipe is a diamond mine in Russia. The owners of the mine plan to cease its operations in 2010 - in favor of underground mining. The mine was discovered in 1955 and is over 600 meters deep.
Sink hole, Guatemala
In 2007, a 300 foot deep sinkhole swallowed a dozen homes in Guatemala - killing 2 and causing thousands to be evacuated. The sinkhole was caused by rains and an underground sewage flow.
Mirny Diamond Mine, Siberia
The Mirny Diamond Mine is 525m deep and has a diameter of 1200m. It was the first, and one of the largest, diamond Pipes in the USSR. It is now abandoned. While it was still operational, it would take two hours for trucks to drive from the top to the bottom of the mine.
Great Blue Hole, Belize
The Great Blue Hole is an underwater sinkhole off the coast of Belize. The hole is 1,000 feet across and 400 feet deep. It was formed as a limestone cave during the last iceage.
Monticello Dam, California
The Monticello Dam is a dam in Napa County, California, United States most noted for its large circular spillway with a rate of 48,400 cubic feet per second.
