St. Margarethen Quarry
The St. Margarethen Quarry is one of Europe's biggest and oldest quarries. The sandy limestone here has been quarried for centuries - and some even went into the restoration of St. Stephen’s Cathedral and the buildings around the Ringstrasse in Vienna. If that sounds old, keep this in mind: some of the stone is 25 million years old. It now serves as an impressive backdrop for concerts and events. Step into this UNESCO World Heritage site for a history lesson you'll love.