A 19th-century artistocrat's mansion, turned into a library, hidden in a modern library.

The metal leaves on this tree are engraved with the names of Holocaust victims.

The mummified right fist of a 1,000-year-old saint-king sits inside an ornate golden reliquary.

Also known as Uncle Karl, the beloved bronze copper keeps a watchful eye on St. Stephen’s Basilica while people rub his lucky belly.

Uh, pardon me, ma'am, but I couldn't help noticing that there's a Columbo statue in the middle of Budapest.

A much-loved sculpture depicting the hero of a 1956 anti-Soviet uprising.

This tomb of a Sufi mystic is a remnant of Ottoman rule in Hungary.

A bronze woman in a stylized dress honors a courageous politician.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

France's most famous cemetery, with some of its most curious tombs.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

The Sun King's military models, saved from the Louvre.

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

This bridge was constructed from the rubble of the infamous Bastille.

Remains of Roman amphitheater hidden in a sleepy quarter of Paris.

The video game-themed street art first popped up in the French city.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

This 400-year-old tree is actually an immigrant from North America.

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

This modest marker near Notre Dame identifies the very center of Paris.

This demon atop the Notre-Dame de Paris looks utterly bored.

This half-forgotten fortress was constructed by the Ottoman conqueror of Constantinople.

A massive marble pedestal is all that remains of a column that towered over Constantinople for 1300 years.

An abandoned Byzantine fortress and notorious prison.