A controversial blue hoop has been puzzling freeway drivers since 2013.

This popular tourist cave was ignored for almost 200 years before being mined into an attraction.

With its webbed walls and bright red coloring, Calgary's iconic bridge looks like a finger trap puzzle stretched across the river.

This private residence was the template for one of the most beloved television homes of all time.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

Staircase winds down the side of Telegraph Hill through gardens, wild parrots flying overhead.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

Eclectic musical collection ranging from hurdy gurdies and orphicas to the Rolling Stones Mobile Studio.

This unassuming cheese empire in rural Oregon churns out more than 150,000 pounds of cheese each day.