This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

The attic of a four-century-old canal house hides a clandestine church.

Dynastic Home of the De Piro Family.

This subterranean necropolis holds three floors of antler-dug grave caves.

The remains of a 1st-century aristocratic Roman town house featuring beautiful well-preserved mosaics.

Burial grounds for more than 1,000 bodies deep under the modern town of Rabat.

This unique building in the main square stands out among the city's typically Baroque architecture.

This spectacular dome managed to survive after being bombed in World War II, in an event known as the "Miracle of Mosta."

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

A sprawling ancient Jewish cemetery with over 30 rock-hewn burial caves.

An ancient underground cultic temple where sunlight penetrates on the summer solstice.

The bluer than blue waters in these natural Israeli caves are reached via the world's steepest cable car.

Macabre astrological automaton clock dating to the late 1400s.

Synagogue built from the stones of Solomon's temple contains the golem of Prague.

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

Biblical beasts and endangered animal preservation come together in this Israeli zoo.

A massive, heart-shaped, wind-carved crater in the middle of the Israeli desert.

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

Once home to seven different roller coasters, Glen Echo has undergone many transformations since its founding in 1891.

Eerie ruins of an abandoned medieval fishing village crumble atop an unforgiving stretch of earth.

The picturesque birthplace of Icelandic democracy is drenched in the blood of its brutal past.

Iceland's largest geothermal mud pool is a little bit haunted and a little bit dangerous.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

This stunning concert hall has become a symbol of Iceland's national recovery.