Earth's tallest volcano is sacred to Native Hawaiians, and home to a dozen world-class observatories.

The strange phenomenon causing gravity to "work backwards" on this hill has been blamed on the paranormal.

Bizarre Cavern.

Abandoned silver mine strewn with wrecked and twisted structures.

The bullet-riddled wall from the St. Valentine's Day Massacre, bloodstains enhanced for your viewing pleasure.

The museum calls itself the "National Museum of the Paranormal" and is full of eerie oddities.

Ralph Waldo Emerson spent two years living here decades before it became a Frederick Law Olmsted-designed park.

The now-abandoned tunnels were built for the transcontinental railroad on the route where the first wagon train entered California.

The abandoned personal amusement park of the King of Pop.

Made of giant chains and hung with shackles, this iron cross honors those unknowns who perished under American slavery.

In the remote high desert of New Mexico, a strange array of poles beckon fury from above.

A picture-perfect town, perfect for blowing up.

A natural gas leak provides a flickering flame beneath a waterfall.

This grand mansion has starred in everything from Bones to Buffy.

A mysterious monument meant to be a guide into "an Age of Reason" was destroyed after an apparent bombing.

All that's left of the quintessential "cabin in the woods."

An acoustic anomaly with a mysterious cause.

A haunting tribute to pioneering photographer Clover Adams.

A painfully obvious spy house sits right across the street from the Russian Embassy.

A dilapidated dock tells the story of Titanic's missed arrival.

Washington's top-secret Cold War-era doomsday communications tower is located in a small neighborhood park.

The tallest The Church of Jesus Christ of Latter-day Saints temple in the world soars above the Beltway.

America's first federal monument.

The final resting place of an unidentified revolutionary soldier sits behind a Virginia church.