This former Roman Catholic Church still contains the embalmed hearts and organs of 22 popes.

This picturesque Umbrian city has a subterranean side that has long remained hidden.

A huge enchanting public park just outside the ancient walls of Rome.

Macabre symbols of death and mummies on display set the tone of this Italian purgatory church.

Southern Italy's spinning top village.

Most famous work of one of Frank Lloyd Wright's sons.

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

At the crypt of St. Mary of Eulogies and the Dead you are left alone to ponder mortality among piles of skulls.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

This 16th-century monastery has been turned into a surrealist architecture compound.

What appears to be an ancient Roman temple is actually a Catholic church.

Reminders of the Battle of Berlin still scar the railway.

These brass bunnies honor the rabbits that dominated the no-man's-land around the Berlin Wall.

What started as a tongue-in-cheek shrine is now a full-blown museum celebrating "The Hoff" and his longtime love affair with Berlin.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

The most visited, and possibly most controversial, museum in Germany.

A secret door leads to this cozy dive that sells only “milk.”

Where the lovelorn find a home for their sentimental keepsakes.

An early work of the architect Álvaro Siza Vieira, these swimming pools blend into the beach.

One of the most beautiful bookstores in the world hides a neo-Gothic interior behind an art nouveau facade.

This restored Portuguese cafe may well be the most beautiful place in the world to grab a Big Mac.

A delightful museum entirely dedicated to the tiny homes of dolls.

A program of Communist glamour in post-Stalin Poland is preserved in this colorful museum.