The only visible reminders of an elaborate engineering project that kept the tower from reaching the tipping point.

This museum housed in a former brothel explores the past and present of sex work in Amsterdam.

The attic of a four-century-old canal house hides a clandestine church.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

Amsterdam's Red Light District leaves little to the imagination.

The water swaps direction twice a day, whipping into a frenzy of whirlpools and rapids.

An automotive, farming machinery, and aviation museum located in Wetaskiwin, Alberta, Canada.

Canada’s surprisingly controversial monument to Dwight Eisenhower.

This massive mall has hundreds of shops, an amusement park, and a history of deadly amusement attractions.

This massive and unusual rock formation near Okotoks is the world's largest known glacial erratic.

A castle built for love, and abandoned due to heartbreak.

A well-preserved Ancestral Puebloan ruin tucked beneath a desert cliff.

Only known mainland rookery of the threatened Stellar sea lion.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

This massive redwood tree has a hole in the base big enough to drive through.

The highest bridge in America was built for an almost unnervingly small amount of money.

A popular swimming hole that hides one of America's most deadly diving spots.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

This geothermal hot spring hides beneath a slowly growing mineral dome.

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

These delicate buggers are some of the rarest fossils that have bubbled up from the Tar Pits.

A beautiful geyser under environmental threat.

The first declared National Monument in the United States.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.