One room inside this building mesmerizes all with its parabolic dome.

On high feast days, the entire blue-glass front of this modern church opens up to reveal the small wooden church inside.

A subterranean display of public art and architecture.

The smallest museum in Basel, Switzerland, is a two-foot-by-two-foot window in the door of a 600-year-old house.

An abandoned swimming pool decays on the outskirts of Berlin.

A spitting ode to a German serial killer.

A stairway to heaven, or to nowhere at all.

Naturally formed white marble arch housed in an abandoned marble quarry from the 1800s.

Along the Rhine, about a mile from the historic Munster, learn the heartrending story of two lovers torn asunder, cast into unknown layers of time and space.

Two stunning 17th-century libraries and a cabinet of curiosities.