An atomic bomb-proof strongbox protects the U.S. Constitution from terrorists and thieves.

One critic described it as "middle Mussolini, early Ramses, and late Neiman-Marcus." Another called it an architectural "natural disaster."

An extensive collection of reliquaries containing the bones of saints housed in the largest Catholic church in Venice.

"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!”

This $3 million model train takes you through Chicago, Seattle, and the thousands of miles in between.

This fort down the Potomac from Washington, D.C. was once the only defensive fort protecting the capital.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

Before Metro, Washington had a robust streetcar network—and you see the remains of this infrastructure if you know where to look.

Decades before the scandal, this staircase on the river was a literal "water gate."

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

The only known Futuro house in North Carolina sits along a stretch of desolate highway on the Outer Banks.  .

This steep cable railway has been hoisting passengers in the heart of Québec City for over a century.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.

Tiki luxury on Nob Hill.

Once America's tallest structure, now a Baltimore landmark.

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

Home to items never before seen by the public.

The only natural lake in the world that drains into both the Atlantic and Pacific Oceans.

A diminutive memorial marks the site of a successful assassination by a right-wing death squad in America's capital.

Just outside of Nairobi lies a large estate surrounded by endangered Rothschild giraffes, who have been fed from the window by Mick Jagger and Walter Cronkite.

A remnant from the golden age of aviation still in use today, Pan Am's Clipper service took off from this Art Deco gem.

Restaurant in Northern Wisconsin comes with a unique feature: a grassy roof covered in living goats.