A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

The fairy tale castle of the "fairy-tale king."

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

This series of underground chambers contains Europe's largest subterranean lake that is slowly drained each day.

The beautiful baroque library of the Hapsburg empire.

The royal seat of Henri Christophe, a formerly enslaved man who became Haiti's only king.

It's estimated that half of the world's gold was mined from South Africa's "golden arc."

Mined to a depth of 240 meters with a perimeter of about 1.6 km, the largest hand-dug excavation in the world.

Largest cave system in Africa.

The largest prehistoric ruins south of the Sahara, once a powerful center of international trade.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."