Near the ruins of a Civil War coastal fortress lies the only known African refugee cemetery in the United States.

A secret, rocky playground hidden amongst the plain white beaches of the Florida coast.

Two men built this castle on the Florida coast as an artistic “landscape sculpture.”

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

A beautiful geyser under environmental threat.

Thanks to a quirk of elevation this gift shop produces magic doughnuts that are found nowhere else on Earth.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

Deadly airliner crash preserved for those willing to climb and pay respects.

Jacksonville's highways rendered this century-old grammar school unusable.

Interactive modern and vintage submarine equipment, World War II relics, and submarine attire.

Swarms of butterflies cannot compare to the awe inspired by the publicly-funded nakedness once displayed in this sunken garden.

The classic Atari game's iconic aliens have invaded downtown San Diego.

Behind this beachfront shop lies a spectacular, colorful sea cave with an equally colorful past.

The iconic Chicago sculpture hides a beautiful and easily overlooked plaque on the backside.

This memorial plaque remembers a strangely shallow maritime disaster known as "Chicago's Titanic."

A retro walk through the history of the tube.

This whimsical campus lawn is dotted with large sculpted numbers and hidden mathematical formulas.

This downtown Dallas art installation is always on the lookout.

One of the last few places in Manhattan that employed a pneumatic systemic keeps it on display.

Commemorating the spot where the famous scientist fed his pigeons.

The original toys that inspired the beloved children's stories are on display at the New York Public Library.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

There must be a pun in this haystack somewhere...