These unassuming lighthouses have seen the first reading of the Pledge of Allegiance, the first wireless transmission, and more than one mystery.

Once in a state of dilapidation, this candy-inspired fortress is now being revived.

Hundreds of glow-in-the-dark objects light up a museum in a historic zinc mine.

Hidden in plain sight on the Hudson River is an abandoned train station where nature has taken over.

World Trade Center memorial likened to a woman's sexual organ.

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

Family-run for more than a century, this pizzeria makes a unique mustard pie.

Devotional offerings and pleas for intercession are left at this Depression-era shrine inside a nature preserve.

Eccentric concrete mansion and museum designed and built by hand from the inside out.

Once America's longest-manned military fort, now an abandoned hulk.

America's "second most important bell" is a contentious spoil of the Civil War.

A wonderous place devoted to art and metal.

A local prank turned town icon.

The world's largest kaleidoscope, designed by a 1960s psychedelic artist.

This old mill and former police station now present a world-class collection of Orthodox iconography.

Thanks to its curved shape, this incredibly durable dam "whispers" to visitors.

It would take 35 firetrucks to fill this enormous glacial pothole.

A park full of outsider art, created by college students studying outsider art.

The internal railway of one of the biggest steel plants in America has been transformed into a linear park with unique industrial views.

A field of nothing but boulders which resembles a giant's gravel driveway.

Whimsical artist house in the New Jersey woods.

This giant disembodied horse head seems to balance impossibly on its nose.

A glittering Thai Buddhist temple in suburban Pennsylvania.

The mastermind behind this palatial hotel perished on the Titanic weeks before its grand opening.