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.

From toys to kettles to scientific instruments, this German museum celebrates the beauty of 20th century design.

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.