This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

Small on the outside, big on the inside, this church is an astonishing act of visual deception.

Installed in an act of one-upsmanship, the annual sundial in this church is also a symbolic victory for the Gregorian calendar.

A marvel of Byzantine engineering under the streets of Istanbul.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

Stalactites and stalagmites in a beautifully lit cave.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

Macabre astrological automaton clock dating to the late 1400s.

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

This sprawling concrete suburb of Kraków was designed by the Soviet Union as the model proletarian city.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

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

Museum dedicated to "the man who moved the Earth."

This man-made mound monument was built out of soil from all across the Polish empire.

The unsettling remnants of a torn down movie set lies nearby the ruined location of the actual Płaszów Labor Camp.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

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

This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

Real bones which are said to have belonged to a Polish dragon.

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

Polish luminaries and masterful folk art find sanctuary in this unique cemetery.