An idyllic swimming pool tells the tale of Hemingway's trouble with women.

St. Augustine's record-setting narrow street was designed to protect against pirates.

The walls of America's oldest masonry fort famously "swallowed" cannonballs.

The famous boat that once ferried Bogart and Hepburn still floats in Key Largo after being abandoned for years.

A building so large that it has its own weather.

This abandoned NASA launch site is now a memorial to a trio of astronauts who were killed there.

An underwater statue of Christ blesses the depths off Key Largo.

A monument celebrating the idea of reaching inaccessible places.

A humid oasis combines recreation with exploration in a unique underwater cavern.

A tribute to Ponce de Leon's supposed quest for eternal youth.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

A luxurious 1880s hotel with its fair share of Tiffany stained glass, Edison electricity, and of course, ghosts.

A mysterious castle built as a monument to lost love.

The scuba diving training facility was named for the steam that rises from the cave's chimney.

Where manatees are the snowbird vacationers in these balmy Florida springs.

The comedy and tragedy of Oscar Wilde is preserved in a Dublin park, captured in a sculpture of colorful stone.

The mummified heart of a saint lives on in this church—after a brief hiatus when it was stolen.

One of Ireland's most infamous prisons for rebels including men, women and children.

An Irish church where an 800-year-old mummy is reaching out of his coffin as if to shake hands.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

This Welsh hotel is the spiritual home of the British 1953 Everest expedition, the first successful ascent of Mount Everest.

The castle still holds traces of the abandoned Roman fort it was built atop.

The longest and tallest aqueduct in Britain can actually be sailed across.

A real-life Professor Snape once taught in this Welsh university building, which students of course nicknamed “Hogwarts.”