Maastricht Underground, Maastricht (must see)

Maastricht Underground is a collection of caves. The caves are also called the Caves of Maastricht or the caves of Mount Saint Peter.

The caves were originally dug in the 13th century to mine chalk. A total of 20,000 tunnels were cut. When lime's value dropped, locals stopped mining. Instead, they started drawing art on the cave's walls. Today, 8,000 tunnels remain spread over 80 kilometers.

During World War II, the caves were used to store paintings. The Night Watch by Rembrandt was one of the paintings hidden in the caves. Rembrandt's famous painting was removed from its frame and rolled into a cylinder for safe-keeping. Locals also stored armaments such as tanks in the cave system.

In addition, over 6,000 locals sheltered in the caves during World War II. The evacuation area features electric lights, a small hospital, a public address system, chapels, a bakery, toilets, and water pumps.

Visitors can explore the caves on a guided walking or scooter tour. It is recommended that visitors bring a coat as the underground caves are quite cold.

Visitors can arrange different tour packages and visit different areas of the caves. The Zonneberg Cave system includes the World War II air-raid shelter. Guests can also see a full-size charcoal version of The Night Watch.

In the North Caves, visitors will descend 30 meters (98 feet) below the surface. This tour features an area where families hid in the caves with their cattle. Visitors can see the oven where the families baked bread.

Visitors can also take private tours or tours catering to kids.