"We gonna rock down to Electric Avenue, and then we'll take it higher..."

These ominous lava formations were said to be an entrance to the netherworld so of course they inspired a famous metal band.

The unique waterfall in Iceland's south features a backdrop of geometric black lava columns.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

Internationally known record store and purveyor of "dusties."

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

Sunset-colored dunes of volcanic ash make taking a poor photo impossible.

A pair of mutilated bronze octopuses slump at the base of the monument honoring California's admission to the U.S.

The stunning interior of this Gothic church is covered in ornate gold details.

The world's largest key collection features keys to the White House, Frankenstein's castle, and Hitler's bunker.

A secluded art gallery hidden within the cellars beneath Tallinn’s medieval monastery.

Ship skeletons haunt Baltimore's waterways.

The wreckage of a World War II bomber is hidden high in the Colorado wilderness.

The massive, incredibly rare instrument is over 11 feet tall with a range so deep it goes lower than humans can hear.

A controversial artwork draws attention to the dark history of Prague's "Suicide Bridge."

An acoustic anomaly with a mysterious cause.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

Unusual hexagonal rocks formed by cooling lava named for their resemblance to traditional Japanese tatami mats.

Thirty creepy ghosts now inhabit this decaying 14th-century church.

A cabinet of curious mathematical models and old calculators.

A grand Gothic Revival basilica with stained glass depictions of Montreal's religious history has only one soul resting in its crypt.

Traditional 15th century Chinese garden in the middle of Vancouver.

Pop culture has helped to keep this iconic British building from being destroyed.