Among the oldest structures in Madrid, these Moorish walls once guarded the medieval city of Mayrit.

This embalmed man is one of the best preserved mummies from the Canary Islands.

A perfectly circular lake is formed by the crater of an ancient underwater volcano.

This hidden collection of everyday objects illustrates life within communist Poland.

The world’s narrowest house makes for an awkward, four-foot-wide living space.

A 20th-century picture show in 3-D.

Warsaw's fantastically preserved gasworks...almost.

A program of Communist glamour in post-Stalin Poland is preserved in this colorful museum.

In the midst of a living monument to Soviet social engineering, Polish Catholics built this church by hand.

Poland's oldest surviving university building holds a wealth of historic science instruments including some used by Copernicus.

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

Relive a Polish uprising via an enormous, century-old cyclorama.

A collection of old neon signs from all over Poland line a secluded courtyard.

A striking public sculpture representing the period of martial law in Communist Poland.