This coal mine is simply HUGE! It produces coal for the power plant nearby. Following wikipedia:
The Bełchatów coal mine is a large mine in the centre of Poland in Bełchatów, Łódź Voivodeship, 150 km west of the capital, Warsaw. Bełchatów represents one of the largest coal reserve in Poland having estimated reserves of 1,930 million tonnes of coal.[1] The annual coal production is around 50 million tonnes.
Annual coal production is around 50 million tonnes!!! Can you imagine?

Fot. Greenpeace Polska, flickr.com, CC license

Fot. Greenpeace Polska, flickr.com, CC license

Fot. Greenpeace Polska, flickr.com, CC license

Fot. Greenpeace Polska, flickr.com, CC license

Fot. Greenpeace Polska, flickr.com, CC license

Fot. Greenpeace Polska, flickr.com, CC license

Fot. Greenpeace Polska, flickr.com, CC license
And below it is the power plant mentioned in the beginning

Fot. Greenpeace Polska, flickr.com, CC license

Fot. Greenpeace Polska, flickr.com, CC license

Fot. Greenpeace Polska, flickr.com, CC license

Fot. Greenpeace Polska, flickr.com, CC license

Fot. Greenpeace Polska, flickr.com, CC license