A Nesting Doll of Churches.

Hitler's bleak vision of relaxation still stands as a mostly abandoned 10,000-room resort complex.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

More sculpture than building, this architecturally significant temple was built on the spot of Saint Peter's crucifixion.

Architectureal fantasy quarter of Rome.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

An abandoned railroad tunnel is now filled with bioluminescent bugs.