The legendary luxury train passage is commemorated with a charming museum inside its former eastern terminus.

A surprising and unconventional mosque hidden in the subsoil of Istanbul.

A sixth-century Byzantine cistern hidden below a modern carpet store.

Liechtenstein's royal family calls this medieval alpine castle home.

A deadly ancient portal to the underworld.

A Turkish ghost town abandoned in a population exchange with Greece.

These tombs were built into the side of a mountain so that ancient angels could reach the dead.

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.

Hidden just under the waters around this Turkish island are the ruins of a once great city.

A mysterious ancient cemetery with Roman sarcophagi and Lycian inscriptions.

This church houses the tomb—but not the remains—of St. Nicholas, the likely progenitor to Santa Claus.

A Lycian city of the dead carved into the hillside of Southern Turkey, complete with startlingly human touches.

Flames have been burning within this mountain for more than 2,500 years.

Roman ruins, natural methane fires and a lovely beach.

Once described as the "Eagle's Nest," this ruined ancient city rests on a remote mountaintop.

This arch granting triumphal entrance into Antalya was designed to honor the emperor's visit.

A tiny chapel and burial site lurk underground in Jajce.

Sip cherry liqueur at a bar dating back to 1840.

Eat the ultimate iteration of Portugal's most beloved pastry.

The tomb of one of the greatest travelers in history.

A scenic UNESCO site that doubles as a habitat for various forms of wildlife.

An unfinished Serbian Orthodox church with 1,389 golden crosses planned to represent the Battle of Kosovo.

A 14th-century Serbian Orthodox church that was once converted into a mosque under the much-disfavored Ottoman Empire.

A UNESCO-protected spiritual seat of the Old Serbian Kingdom and Empire.