The city of Potosi in southern Bolivia was built on the proceeds of a huge mountain above the city which was once full of silver and other precious minerals. The city was once important and as big as Paris at one time. The silver was taken from the mountain and shipped to Spain. The Spanish became wealthy from the mines and brought in slaves and used the locals to extract the minerals. A million people are said to have died in the 400 years since the silver was discovered. Today the miners continue to search for elusive veins of minerals using methods not very different to the original miners. Life expectancy for miners is very low and the dust in the mines lead many to early death from silicosis.
The city itself still has many of the once grand buildings but they are derelict and weathered and the former rich owners have long since gone. It is a poor city and the mines bring income to some but others scrape a living from what is left in the mountain mainly with their bare hands and hammers. Its a grim lifestyle but the promise of hidden riches and the lack of any other employment keep the men of Potosi in the mines.
The smoking devil in the clip is the mines guardian, the miners leave him cigarettes and alcohol and bags of coca leaves to bring them good luck when they in the mine.