The Hallstatt salt mine is the world's oldest working salt mine

The Hallstatt salt mine is the world's oldest working salt mine. The mine is located within the Upper Permian to Lower Triassic Haselgebirge Formation of the Northern Limestone Alps. The Hallstatt salt mine comprises 21 levels and several smaller shafts ranging from 514 metres (1,686 ft) above sea level (Erbstollen level) to an elevation of around 1,267 m (4,157 ft) (Erzherzog Matthias Schurf level).