Sail through this subterranean show cave that is home to a legend that would go on to name nearly everything around it.

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

This community on a small Venetian island has taken to painting their houses in bright neon hues.

A tree grown from astronaut seeds which were exposed to cosmic rays.

This remarkably simple jail went over a century without an escape.

Every year, over 25,000 monarchs overwinter in Pacific Grove.

Two rocks in a perpetual kiss and one of "the most romantic spot in America."

A music-filled, booze-soaked oasis in the desert.

The only theatre in the world constructed specifically for sound movement.

Medicinal spa created from the mineral-rich runoff of a geothermal power plant

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

This Japanese-inspired labyrinth of hot springs is hidden in a Chilean forest.

Pablo Neruda's custom-built lover's nest was made to remind him of the sea and named after his mistress' hair.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

Cat art as far as the eye can see.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

Blighted Irish field and the ruins of a 19th-century cottage on the edge of urban Manhattan.

America's Most Wanted's set resides in this tribute to the history of crime and punishment.

Once the tallest building in the world and the site of “the highest dinner ever held in New York” this building now holds the most expensive penthouse in the city.

Yale University's home for rare works, including the mysterious Voynich Manuscript.

One of the deadliest American air disasters is nearly forgotten in Brooklyn.

Here’s how Robert the Doll earned his reputation as the most haunted doll in the world.

Unrepaired walls from a 1920 anarchist bomb attack.