This stately monument has been wearing a traffic cone hat for decades much to the delight of the locals.

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

Look closely and you’ll notice that the color changes a third of the way up the tower.

One of the most influential presidents in U.S. history wanted only this plain, elegant monument as his lasting memorial.

The preamble to the U.S. Constitution written entirely from vanity license plates hangs in the Smithsonian museum.

This elaborate towering structure was once famed for its revolutionary height.

Huge masonic hall in Philadelphia with lavishly themed rooms.

Holding multiple historical boats and an entire 19th century village, this New England attraction is the largest maritime museum in the world.

A large camera obscura, constructed entirely from digitally fabricated components.

A tribute to the hard-working men and women of Grumman, who crafted F-14 fighter jets.

An abandoned water sports stadium that has become a haven for graffiti and decay.

The "beautiful" equation predicting the movement of all electromagnetic particles is engraved in front of Newton's tomb.

This long-hidden space above Westminster Abbey now displays the battle gear of the legendary King Henry V.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

This former “ante-chamber to the guillotine” has been refurbished to illustrate the brutal history of French justice.

The attic of a four-century-old canal house hides a clandestine church.

An eccentric playboy's astounding natural history collection.

A millionaire's abandoned swimming pool from the gilded age of one of America's most distinguished families.