Mir Mine is an abandoned open pit diamond mine located in Mirny, Easter Siberia. The minie is 525m deep and has a diameter of 1200m. It was the first and one of the largest diamond pipes of the USSR. Mir Mine was discovered in 1955 and was operated for almost 50 years, finally closing in 2004. While in operation, Mir Mine gave out 2 million carats anually. It takes a truck 1 1/2 to 2 hours to get to the top if it starts at the base floor. The air zone within this mine is closed for helicopters - a few accidnts occured when they were "sucked in"by downward air flow. More pictures at link below.