The perfectly preserved underground rooms where Churchill plotted the war against Germany.

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

The 80-foot tire that looms over Michigan's I-94 was once a Ferris wheel in the New York World Fair.

Astounding collection of coin-operated games and automata.

Concrete igloos standing across from what remains of the Michigan Central train depot.

The bones of an old zoo crumbling in the shadow of a new one.

Hidden beneath the streets of London is a secret subway that only carried mail.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.

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

Catacombs turned marketplace.

A historic London pub with prison cells in the cellar and a "spy room" on the second floor.

The world's longest known cave system.

Fragments of architectural wonders from around the globe are embedded in the newspaper building's walls.

This replica of the Greek structure is in the heart of Nashville.

A crumbling mountain resort that looks like it was abandoned in an instant.

Controversial tribute to the heavyweight champion boxer who grew up in Detroit.

An angular maze of concrete in Grand Rapids acts both as public art and as a staircase for fish traveling upstream.

The only surviving prototype for Buckminster Fuller's house of the future.

A Beaux-Arts triumph rises from decades of decay to become the heart of a new innovation district.

Island where motor vehicles are banned -- home to the only carless highway in the United States.

This national park on the shore of Lake Michigan features remarkable dunes that lie at the heart of a Chippewa legend.

These enduring murals depicting a distinctly Marxist tribute to capitalism could not even be defeated by McCarthyism.

What was once the largest NFL stadium.

A sealed test tube said to hold Thomas Edison's dying breath was given to the inventor's friend and mentee, Henry Ford.