Last week, Quartz visited one of the world’s largest bitcoin mines, located in a decaying industrial park on the outskirts of the city of Ordos in Inner Mongolia. The mine is operated by Bitmain, one of the most influential companies in the $70 billion bitcoin economy. Bitmain operates seven warehouses mining bitcoin and one facility that mines litecoin, another fast-growing digital currency. It also contains a repair facility where workers fix the bitcoin machines.

This is what it’s like to walk around the Ordos mine:

The compound contains eight buildings and 25,000 mining rigs

The first building we entered was the one for litecoin mining

This is one of the seven buildings for bitcoin mining

These are the repair rooms where more serious technical fixes are made