Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

This pebble beach is so beautiful that taking its rocks is against the law.

An architectural marvel that spans the Arda River, and has stories of a haunted past.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.

A replica that won't float away.

The oldest church in Iceland is one of the few to feature ornate decoration.

Former meatpacking facility turned vertical farm and sustainable business complex.

New York City's only preserved family home from the 19th century.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

The walls of the iconic dome are hollow and have a secret stairway.

This painted blacktop brings the classic arcade game to life.

Wall to wall taxidermy at Denver's oldest and most exotic steakhouse.

Hundreds of hidden passageways weave through the old quarters of Lyon.

Tour the original street level of Port Angeles, buried underground in 1914.

More than half of this Indian palace is drowned but it looks all the more spectacular for it.

Nine of the very few concrete ships ever made in the U.S. are beautifully decaying off a Virginia pier.

This artificial cave looks like something out of a fairytale.

With well over 130 falls and cascades to brag about, Hamilton, Ontario has earned its stripes as the waterfall capital of the world.

Six beautiful wooden giants are hidden around Copenhagen.

"I did this all while you were watching TV."

Oldest existing church in New York and the inspiration for Washington Irving's "The Legend of Sleepy Hollow."

Cemetery featuring rare glass-fronted columbarium.

The end of the 4 Line is also the end of the line for 300,000 souls in one of NYC's most illustrious cemeteries.

An Iron Age fort on the edge of a seaside cliff offers a glimpse into an ancient, mystical world.