Where the U.S. government kept its actual treasure, before Fort Knox.

A sweet symbol marks the place where torturous executions were once carried out.

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.

The "Seinfeld" diner.

The grand marble structure next to the White House is Andrew Carnegie's temple to Pan-American diplomacy.

The walls of the iconic dome are hollow and have a secret stairway.

The elevator that makes it possible to fly American flags in bulk over the U.S. Capitol

A red sandstone freestanding monolith rises out of the sea in northern Scotland.

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

"Congress may voluntarily remain in session throughout the summer, in order that our Congressmen may be protected from the intolerable discomforts and dangers of the ordinary outdoor weather!”

A plaque hangs near the execution place of the Scottish Independence leader famously depicted in "Braveheart."

A portly statue of a golden boy commemorates an unusual cause of the Great Fire of London: the sin of gluttony.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

A hidden treasure in London with a rich medieval history, and the resting place of many luminaries.

Displaced highlanders would take shelter from the wet Scottish climate under the large walled bridge at Glasgow Central Station.

The heads of two giant mythological water horses honor Scotland's horselord past.

The filming location of a shark attack in Steven Spielberg's famous shark movie.

Crammed into a Baltimore row house is an oddities shop that sells everything from skulls to dead insects.

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

The tallest The Church of Jesus Christ of Latter-day Saints temple in the world soars above the Beltway.

At 207 feet, one of the world's longest continuous escalators.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.