Bingham canyon mine, Utah

this is supposedly the largest man-made excavation on earth. extraction began in 1863 and still continues today, the pit increasing in size constantly. in its current state the hole is 3/4 mile deep and 2.5 miles wide.

apparently the largest ever hand-dug excavation in the world, this 1097 metre deep mine yielded over 3 tonnes of diamonds before being closed in 1914.the amount of earth removed by workers is estimated to total 22.5 million tonnes.

glory hole - Monticello dam
A glory hole is used when a dam is at full capacity and water needs to be drained from the reservoir.
this is the glory hole belonging to Monticello dam in California and it ��s the largest in the world, its size enabling it to consume 14 ��400 cubic feet of water every second
Great blue hole, Belize

situated 60 miles off the mainland of Belize is this incredible ��geographical phenomenon �� known as a blue hole. there are numerous blue holes around the world but none as stunning as this one.