This railroad and oil tycoon's lavish estate now stands as a time capsule of the Gilded Age.

Like Mardi Gras, only everyone's a pirate.

Intertwined, interspecies trees which locals believe can grant boons to lovers.

The world's largest occupied bat houses hold hundreds of thousands of flying mammals.

An 18th-century Spanish watchtower made entirely of seashell and concrete.

This ancient octopus-like tree was saved from destruction thanks to shady reporting.

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

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

This Florida sinkhole hides a rainforest-like micro-environment in its depths.

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

The most loyal of little dogs, or a Victorian era publicity stunt?

This otherwise ordinary close on the Royal Mile constituted the end of the world for Edinburgh’s poorest residents.

Largest lake in Great Britain measured by surface area.

Near the former site of numerous witch burnings, this lavish Edinburgh mainstay pays homage to Scotland's brutal history.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

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

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

Polish luminaries and masterful folk art find sanctuary in this unique cemetery.

St. Mary's features one of the most spectacularly decorated cathedral interiors in all of Europe.

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

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

Real bones which are said to have belonged to a Polish dragon.

An underground city of salt.

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.