An artist's mausoleum with a haunting echo.

Home to three historic ships from the age of Vikings.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

A Roman spa buried deep beneath the City of London.

A mysterious pair of mice eating a piece of cheese is London's smallest public sculpture.

The commemorative stone column conceals a secret laboratory.

The Great Fire of London and the regulation of one-way streets both started in this alley.

Now a memorial to merchant sailors and Titanic victims, this medieval church was destroyed by bombing raids in 1940.

The bombed out remains of the old church were kept intact next to the new one, as a reminder of the futility of war.

The contents of this safe survived a 37-kiloton nuclear bomb.

Twice a year, visitors can tour the desolate site that birthed the Atomic Age.

On October 26, 1963, a 12-kiloton nuclear device was detonated here in granite some 1,211 feet below the ground surface.

Celebrating the Swedish ship used in the first Arctic expedition to navigate through the Northeast Passage.

This Stockholm art museum integrates many of its pieces into the surrounding outdoor areas and natural landscape.

The center of Stockholm can be found along this quiet street.

A 130-year-old urinal is the oldest of Stockholm and perhaps all of Sweden.

A wooden street sign is the last remnant of this 400-year-old alleyway.

A Stockholm metro station is home to an escalator that is not only the longest in Sweden, but among the longest in the world.

A 12th-century church with a medieval fresco and an intriguing “Greek runestone.”

Sweden's oldest animated sign is still lighting up the skyline today.

Although rarely used, there is still a hidden room for the royal family at the Stockholm central station.

When this 18th-century observatory's meridian was moved, it set Sweden's time back by 0.04 seconds.

"Only the dead get off at Kymlinge."

Located in an old church, this brewery produces a different kind of holy water.