At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.

This historic "City of the Dead" lies prominently in the center of New Orleans' famous Garden District.

Wild lights and sound effects turn a walk through some caves into an eye-popping 1960s tourist attraction.

This symbolic piece of New Orleans architecture is also home to a few ghastly stories.

The private clubhouse for the members of the Academy of Magical Arts.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Left untouched since a double murder-suicide in the 1960s, Los Feliz murder mansion remains a neighborhood mystery.

One of the oldest used bookstores in the U.S. has been selling antiquarian treasures since 1825.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

These delicate buggers are some of the rarest fossils that have bubbled up from the Tar Pits.

A hidden network of subterranean passageways lies tangled beneath Indianapolis' bustling City Market.

This strange seaside tower got its name from a wealthy eccentric who would hide coins among its stones.

The atmospheric road was never meant to be so creepy.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

360° views of the city plus five floors of optical illusions and hands-on science.

Staves, storm-calling, and of course, necropants.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

Hollowed out cedar log tubs set in an ancient towering forest.

A strange house built only at night, with rumored mystic inspiration.

Famously misunderstood wonder of the ancient world

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

The most iconic structure in Scotland has been home to bishops, colonels, and Sean Connery characters.

The ghostly remains of an accidental sea.

A hands-on traveling collection of the innovative devices of yesteryear.