The only Frank Lloyd Wright-designed structure in the architect's hometown.

What appears to be a wizard's lair in Milwaukee actually houses a massive water pipe.

The notorious headquarters of a corrupt political machine.

Avoid gangster interaction while window-shopping.

An uber-secure, windowless tower of doom in the center of Manhattan is an NSA spyscraper.

The remnants of what was once the largest film studio on the East Coast are hiding in plain sight.

Walk through the actual strap iron cells and solitary chambers of Arizona Territory’s first prison.

This striking art museum holds an amazing series of curiosity cabinets.

The niches over the western entrance of Westminster Abbey honor individuals from the 20th century who gave their lives for their Christian beliefs.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

A bypass decorated with large wooden troll carvings.

The bugs crawling down the front of this office building are almost as big as a '68 VW Beetle.

Over thousands of years, this slot canyon was carved out of the bed of an ancient lake.

Three playfully immersive mini golf courses let you travel alongside your ball to the cup at this facility, which has been around since the 1950s.

This forgotten beach house built to look like a Frank Lloyd Wright masterpiece overlooks a hidden beach.

The arboretum whose marshy soil sucked up the dreams of housing developers.

A gothic church spire sits atop this skyscraper, the tallest church in the world.

A 400-foot-tall tall map of Chicago makes this once-ignored building stand out.

The fanciest public restroom in New York City boasts fresh flowers, art, and a classical music soundtrack.

This striking arch, one of the first architectural elements constructed in Prospect Park, was recently restored to its original glory.

A wooden rollercoaster that still delivers a thrill.

This hotel was the site of major events in sports and radio history. It was also used as a detention center during World War II.

This wall on a street corner in Lower Manhattan has been a blank canvas for a rotation of renowned artists since the 1980s.

Pulled from the rubble of one of the worst modern tragedies, a steel crossbeam became a symbol of hope for New Yorkers.