The spot where the two men ate together now stands enclosed in glass.

A forgotten Cold War relic hidden in the outskirts of a Wisconsin city.

One of the first schools in the U.S. to admit students without regard to race or gender.

A fearsome dragon clings to a corner of Munich's city hall.

Rifle through images of skyscrapers, Worlds Fairs, and more in the largest public postcard repository in America.

An off-the-beaten-path place to literally hang beneath Milwaukee's Holton Street Bridge.

When waves crash onto this section of beach, the rocks sing a song.

To truly appreciate Detroit's landmark skyscraper, you have to step inside.

A careful eye can find hundreds of dinosaur tracks running along the Connecticut River.

Though strikingly beautiful, Seattle's other railway station is now largely forgotten.

Every birth, death, and marriage is recorded in these color-coded leather-bound books.

Whimsical woolen creatures have taken over this historic Northern Ireland park.

A sophisticated astronomical tower built by one of the greatest Persian scholars of the Islamic Golden Age.

This ruined medieval castle was the scene of Lord Robert Dudley’s seductive reception for Queen Elizabeth I.

To find the "unicorns of the deep" you've got to go downstairs.

A golden egg-shaped sauna in the Arctic tundra.

Driftwood dinosaurs lurk within trees covered in a rainbow array of avian abodes.

The red letters in the literary pavement leading to the library form a mysterious code.

An ancient passage filled with stalls selling used books, once frequented by Vincent Van Gogh.

Rusty pieces of metal jutting out of a breakwater are all that's visible of the 12,500-ton ocean liner that capsized just off the beach.

The romantic botanic tunnel feels like a well-kept secret.

This 11th-century temple gave rise to the word "juggernaut," as well as some mysteries that defy scientific explanation.

This 1830s store is believed to be the site of Harriet Tubman's first stand.

A spectacular rainbow of stained glass makes the "Pink Mosque" one of the most beautiful in Iran.