A private collection of massive steel monsters guarding a Texas pipe works.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.

If you want to take a peek at Area 51, this is legally as close as you're going to get.

This 29-ton granite ball spins around at the slightest touch thanks to a scientific phenomenon.

A nearly 500-year-old sculpture depicts a man eating a sack of babies, and no one is sure why.

This massive blockhead sculpture hides an entire library.

For the holidays, the tallest broadcasting tower in the Netherlands turns into one of the world's tallest Christmas trees.

An ornate plague column – built to celebrate life – claimed the lives of numerous artisans during its construction.

This psychedelic tourist trap is a leisurely descent into madness.

An ever-growing field of footwear invites legends and more shoes.

Monument to a brutal, ineffectual US bombing campaign and a sobering reminder of the human cost of the Vietnam War.

Parking garage where Bob Woodward met Watergate source "Deep Throat."

Mysterious meeting place for UFO hunters near Area 51.

Brightly colored 30-foot-tall totems light up the desert sky just outside Las Vegas.

An acoustic anomaly with a mysterious cause.

The highest point in Belgium is a staircase to nowhere.

A tribute to an iconic act of defiance from the Croatian War of Independence involving a small car.

The world's longest known cave system.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

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

World's first "penitentiary," meant to be humane, drove men insane.

Home to items never before seen by the public.

The granddaddy of all tourist traps, built on ice water, jackalopes, and a giant dinosaur.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.