The Tagebau Hambach is a large strip mine (Tagebau) in Niederzier

Niederzier

Niederzier is a municipality in the district of Düren in the state of North Rhine-Westphalia, Germany. It is located approx. 10 km north of Düren, and 10 km south-east of Jülich....

 and Elsdorf

Elsdorf

Elsdorf is a town in the Rhein-Erft-Kreis, in North Rhine-Westphalia, Germany. It is situated approx. 5 km south-west of Bergheim and 30 km west of Cologne....

, North-Rhine Westphalia

North Rhine-Westphalia

North Rhine-Westphalia is the most populous state of Germany, with four of the country's ten largest cities. The state was formed in 1946 as a merger of the northern Rhineland and Westphalia, both formerly part of Prussia. Its capital is Düsseldorf. The state is currently run by a coalition of the...

, Germany. It is operated by RWE

RWE

RWE AG , is a German electric power and natural gas public utility company based in Essen. Through its various subsidiaries, the energy company contributes electricity and gas to more than 20 million electricity customers and 10 million gas customers, principally in Europe...

 and used for mining lignite

Lignite

Lignite, often referred to as brown coal, or Rosebud coal by Northern Pacific Railroad,is a soft brown fuel with characteristics that put it somewhere between coal and peat...

. Begun in 1978, the mine currently has a size of 33.89 km² and is planned to eventually have a size of 85 km². It is the deepest open pit mine with respect to sea level

Sea level

Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...

, where the ground of the pit is 293 metres (961 ft) below sea level.