A gorgeous, Gaudí-esque stairway constructed in the city of Istanbul by a prominent Jewish family.

Remnants of successive wars and Muslim colonialism in the 11th century.

Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

Carvings in Turkey's Marble Road may have directed ancient Romans to a hidden brothel.

The ancient latrines of the Greeks, in all their public glory.

The alleged house of the Virgin Mary is tucked away in a park and nature preserve on Mt. Koressos in Turkey and is holy to both Catholics and Muslims alike.

Large miniature theme park with 100-plus models.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

An abused and forgotten metropolis, abandoned for centuries.

A deadly ancient portal to the underworld.

Roman ruins top white travertine terraces formed by ancient hot springs.

A fountain standing as a testament to a doomed alliance.

Noirish green neon marks the location of one of the oldest private detective agencies in France.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

Romania's triumphal arch looks out over Bucharest.

This memorial to the victims of the Romanian Revolution of 1989 is often compared to a potato on a skewer.

This communist behemoth is the heaviest building in the world and a legacy of a brutal regime.

This once-derelict building is now one of the most beautiful bookstores in the world.

This elaborately decorated, fairytale-like Romanian royal palace is one of the most striking castles in Europe.

Time stands still at this serene burial ground in the center of Budapest.

This historic hotel preserves many treasures from its heyday hosting passengers on the Orient Express.