While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

Decades before the scandal, this staircase on the river was a literal "water gate."

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

There’s a hidden military meme engraved on the World War II Memorial.

The exorbitant price of paradise.

An oddities shop that dabbles in the deathly and beautiful.

This London marker celebrates the spot where the world-famous English band was founded.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

Where condemned pirates met their grisly end at the gallows on the River Thames.

This one has sailed five times as far as Sir Francis Drake's famous ship.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

A plaque hangs near the execution place of the Scottish Independence leader famously depicted in "Braveheart."

The London pub overlooks where the Mayflower was moored before setting sail for the New World.

After nearly 60 years, there's still a bear at Paddington Station looking for help.

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

This picturesque horseshoe weir was first built in the 1600s to prevent flooding in the town of Bath.

This park feels like a lush little jungle full of wildlife nestled within São Paulo.

This singular art museum in São Paulo is unique inside and out.

The pedestrian traffic signals in Brazil's teeming metropolis light up with clues to nearby landmarks.

One of São Paulo's tight urban intersections has become a haven for graffiti artists ever since a single Batman started the trend.

This massive Brazilian church is built like an angular, technicolor pyramid left by Mayans from the future.