Marienfeld is a large (2.6 km² / 640 acres) grassy field on the reclaimed site of a former open-pit lignite mine about 20 km (12 mi) south-west of Cologne Cathedral in the city of Cologne, Germany, straddling the towns of Frechen and Kerpen. The mine area was named Marienfeld (German: Mary's Field) and landscaped in order to serve as the site of the Catholic Church's 20th World Youth Day in 2005.
Read more about Marienfeld: Overview