A perfectly circular lake is formed by the crater of an ancient underwater volcano.

A magical sinkhole on the Yucatán Peninsula is adorned with mini waterfalls and hanging vines.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

A castle built for love, and abandoned due to heartbreak.

This popular cave pool is truly magical, despite the crowds.

Don't be fooled by this fake medieval facade even if it is almost 300 years old.

An alleyway plaque is all that remains of the independent Texas' envoy that forgot to pay their rent for over a century.

The remains of Crystal Palace Great Exhibition of 1851.

In this cobwebbed old operating theater, you can practically hear the screams of the unanesthetized patients.

This former asylum for Black Americans is haunted by its history of violence and racism.

This whimsical stacked cabin looks like something out of a children's book.

A stone arch leads to a cavernous 1930s spring house tucked away in the Pennsylvania woods.

The burning of this 12th-century church kicked off a campaign of Norwegian Black Metal terror.

Vikings and Evangelicals have both had a hand in this replica medieval church.

An intricately carved Viking church overlooks a glistening fjord.

This campus chapel is Robert E. Lee's final resting place and a topic of debate about the legacy of the Civil War.

The remains of a historic plantation nestled in between a parking lot and the rental car return at Reagan National Airport.

The oldest arched-covered bridge in Virginia has truly withstood the test of time.

Herbert Hoover's "Brown House" rural presidential retreat was a PR disaster amid the start of the Great Depression.

A genuine Tudor manor transported piece by piece from England.

Hear, smell, see, taste, and touch history at this immersive Civil War hospital.

An innovative attempt to break a siege in the American Civil War still scars the earth today.

An eight-sided home built during a brief octagon craze in the 1850s.

The Virginia farm where John Wilkes Booth met his grisly end is now largely forgotten.