Ferropolis, a “city of iron,” is an open air museum of industrial relics, with five giant excavators looming on a peninsula in the Gremmin lake of Gräfenhainichen, Germany.

The site was once a GDR-era coal mine, and a museum on site tells the history of that industrial period. Yet most impressive is the spectacle of the towering, mid-20th century machines, which regularly provide a backdrop for music festivals and other events held at Ferropolis, which was started in 1995.

The machines measure up to 130 meters long (427 feet) and 30 meters tall (98 feet), and include such now-obsolete mechanical monsters like the Racehorse — a 221 kilo crawler swing excavator. For some of the machines, you can even climb on board for panoramic views of the surrounding area.