This Orthodox Church's exterior is rather unorthodox.

Disks are rolled out onto the south lawn to absorb the impact of Marine One's wheels like giant coffee coasters.

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

Daredevil repair workers can worm their way out the access hatch, loop ropes over the apex and rappel down the monument.

Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

A little lighthouse in New York City, surrounded by mysterious stories of insanity-driven construction.

The first and only carousel with a lineup entirely of insects.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

This outpost of America's most popular fast-food restaurant is housed inside a palatial mansion.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

To find the "unicorns of the deep" you've got to go downstairs.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

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

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

Yo, Adrian!

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

This whimsical fountain pays tribute to Toronto's four-legged friends.

An isolated beacon with a history of grisly murder and a view of some of literature's greatest inspirations.

The former estate of the Guggenheims, part of the opulent Gold Coast that inspired the Great Gatsby.

A 98-room castle in the middle of Toronto that bankrupted a 19th century electricity multimillionaire.