10 Massive Natural And Man-made Holes In The World
Mirny Diamond Mine
The Mirny Diamond Mine is currently over 500 meters deep, and has an impressive diameter of 1,200 meters. It was considered to be one of the first and largest diamond pipes ever built in the USSR, but has since become abandoned.
Great Blue Hole
The Great Blue Hole is the single most impressive hole in the planet. The underwater sinkhole is located just off of the coast in Belize, and is 1,000 feet across and over 400 feet deep. It was formed by a limestone cave sometime in the previous ice age.