Quite possibly the oldest love poem known to humankind.

Legend says if you stick your thumb in the hole and it gets wet your wish will be granted.

A marvel of Byzantine engineering under the streets of Istanbul.

This crucial gathering spot along the "hippie trail" still displays old notes between traveling beatniks and backpackers.

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

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

No one is sure if the world's fourth-largest diamond had been found in a rubbish heap or was pawned by Napoleon's mom.

Housed in an old British jail, this spot serves up Georgian, Russian, and Ukrainian specialities with a side of Turkish history.

One of the largest wooden constructions in Europe was meant to be a casino, but soon became an orphanage.

A rooftop restaurant hides in plain sight atop Vienna's Palace of Justice.

Those who own or stay at this 500-year-old, allegedly cursed house often meet terrible fates.

Berliners converted a bombed-out, disused lot into a community-run urban farm with its own cafe and bar.

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

The oldest amusement park in the world has been providing a nice spot to have some fun since the 1500s.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

Copenhagen's celebrated theme park and gardens.

Architecturally stunning library serves as the hub of Finnish scholarly life and culture.

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

Dine on food tied to Viking history and legend at this subterranean Stockholm spot.

Maybe the only restaurant in the world where your seat will be signed by a Nobel laureate.

Sound travels strangely in this underground whispering gallery.

The 19th-century home of Count and Countess von Hallwyl is now a museum.

Stockholm's deepest subway station is also a stunning ecological wonder.

This restaurant combines two Finnish traditions in one place: warm-weather relaxation and outdoor carpet-cleaning.