A lesser-known part of the Kinsey Institute is this impressive collection of art, artifacts, and material culture related to human sexuality.

A stunning, abandoned limestone quarry in southern Indiana provided the stone to erect the Empire State Building.

A turn-of-the-century architectural marvel built on healing mineral springs and salt licks.

A warning to the weak-kneed: This narrow bridge does its swinging eight stories high.

An unexpected but incredible collection of wildlife dioramas spanning rainforests, swamps, forests, and plains.

You thought Santa Claus didn't exist, but it turns out you were wrong.

This historic cliffside mansion uses a natural cave for air conditioning.

This abandoned 19th century orphanage started as a boarding school for children of Civil War veterans.

A massive bur oak tree believed to be some 500 years old is the centerpiece of this quiet urban greenspace.

Patrick Dougherty's fantastic living tree sculptures, mind-blowing but temporary.

An amazing collection of scale model ships.

The legacy of an unsolved, gruesome murder rests beneath the spans of this historic bridge.

River pirates, murderous bandits, and serial killers used this Illinois cave as their debauched hideout.

The world's largest collection of the world's largest objects is in one small Illinois town.

An enormous natural sandstone bridge in Kentucky.

In the Shawnee National Forest, amazing rock formations peer through the treeline.

A once-booming Mississippi River town with a history of racial violence is now eerie and mostly abandoned.

This majestic tree has survived 400 years of storms, droughts, and floods, and is a beloved natural landmark in Missouri.

A geological oddity formed by two rivers carving out a mass of limestone on both sides.

Two Ming Dynasty lion statues guard the entrance to the journalism school.

This Mediterranean castle was built for a millionaire and his giant dog.

Curious cave that stays a cool 56 degrees all year long.

Once an ambitious nature spa, these forest ruins now provide a serene monument to failure.

The maximum security facility was once thought to have "the bloodiest 47 acres in America."