BBC Focus magazine have a feature called Megapixel in every edition where they feature mind blowing images. The edition I’m reading a the moment features Mir Mine in Mirny, Eastern Siberia, Russia. It’s a former open pit diamond mine and is 525 meters (1,722 ft) deep with a diameter of 1,200 m (3,900 ft). It’s the second largest excavated hole in the world, after Bingham Canyon Mine. The airspace above it is closed for helicopters because of incidents in which they were sucked in by the downward air flow. Insane.