Delving deep Jun 24 2014
From Bernhard Lang, aerial photos of the largest made-made hole in Europe, the Hambach Mine in Germany. The mine was started in 1978, is 1150 feet deep, and will eventually encompass an area of over 32 square miles. Here's the mine on Google Maps; it's huge.
That's a photo of one of the massive mining machines used to extract lignite (aka "brown coal") from the mine. The machines are almost 800 feet long and 315 feet high...those yellow specks to the right of the machine are likely fairly sizable construction trucks. (via co.exist)