Caves of Maastricht

[1][4][3] During World War II, the quarry was used to store valuable paintings and armaments that could be used against the Germans, including a proposed force of 30 tanks that would sortie against the Germans that was timed to attack at the same point of liberation.

[citation needed] In addition to the military, over 6,000 citizens took shelter in the quarries during World War II.

Among the paintings hidden in the quarries during WWII was The Night Watch by Rembrandt van Rijn.

The canvas which measures 363 × 437 cm was detached from its frame and rolled into a large cylinder.

A large portion of the former tunnel system no longer exists as the encompassing limestone was quarried in an open-cast mine operated by ENCI.