A small triangle of DC grass is the final resting place of one of Sonny and Cher's songs.

A much-maligned monument to teetotalism.

Light bulbs, scrap wood, and tinfoil comprise this homemade throne of the gods.

The house where John Wilkes Booth conspired with his co-conspirators.

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

The most decorated dog of World War I is preserved in the Smithsonian.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

Perhaps the most scandalous statue of America's first president.

This Soviet-era "closed town" was a top secret uranium producer often left off of maps.

The monster at the center of the Darwin Center Spirit Collection.

Hidden beneath the streets of London is a secret subway that only carried mail.

This beautiful example of Victorian engineering is the oldest water-balanced funicular anywhere in the world.

The nearly 200-year-old folly has a secret spiral staircase hidden in one of its pillars.

A statue honors the children who fought Nazis in Poland.

Late at night, the bust of the "Dracula" actor was snuck onto the facade of this Budapest castle.

This bronze statue was erected to honor a small Scottish town's beloved stray cat.

This century-old grotesque has a mysterious history and may not actually be a rabbit.

Human-made caves excavated to hide a secret society of wealthy pagans.

J.R.R Tolkien, C.S. Lewis, and other "Inklings" met at the Oxford pub to discuss the now legendary fantasy stories they were writing.

An Oxford museum where visitors can have tea with the Mad Hatter and climb through the wardrobe to a fantasy land.

Lyon, France is home to two remarkably preserved Roman theaters, one dating back to 15 BCE.

For hundreds of years, automatons moving to metallic music have been marking the passage of time.

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

The broken skateboards that became a poignant memorial to a murdered skater.