There might not be much left of these Irish ruins, but their linguistic legacy is still going strong.

A fairytale Gothic castle steeped in Nazi treasure conspiracy theories.

This centuries-old pub boasts a collection of more than 4,500 snippets of neckties from around the world.

The stoic structure boasts a whimsical set of stained glass art commemorating Lewis Carroll.

Once one of the largest rooms full of books in the world, this bookstore basement is still a treat for bibliophiles.

This fairy-tale, neo-Gothic church in the Azores is a world of magical realism.

The hidden lair of an alchemist rediscovered in a 2002 flood.

Take a steam-powered ride straight out of the past on this Appalachian rail line.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

Near Birmingham, England three and a half miles of top-secret tunnels housed a World War II “shadow factory” and a Cold War nuclear bunker.

Romania's "Red Ravine" is a little-known natural wonder that bears a resemblance to the Grand Canyon.

Ruins of a historic medical facility sits eerily by the water.

A pre-Industrial Age iron furnace and the site of a nearly-forgotten piece of Black history.

A modern Nordic Pompeii on the Icelandic island of Heimaey.

This exceptionally well-preserved ancient marvel also houses a small museum dedicated to Jordanian folk tradition.

Gladiators battle and chariots race daily in the ruins of a once-great Roman city.

Monkeys lounge around at this 13th century temple.

A Lovecraftian altar of nightmarish bronze chairs sits ominously on a boardwalk in Puerto Vallarta.

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Abandoned railway line circling the city of Paris.

The hidden "ballroom" under a mansion lake was built by a criminal who ate a cyanide pill during his trial.

The most iconic structure in Scotland has been home to bishops, colonels, and Sean Connery characters.

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