This extraordinary Depression-era expenditure was modeled after a postcard of a Mediterranean hotel.

The biggest solar telescope in the world helps reveal the secrets of our sun.

A reproduction of earth's many biomes.

America's only nuclear missile silo open to the public.

The world's largest military aircraft cemetery.

In Tucson a giant metal snake helps pedestrians cross a busy highway.

This iconic 1958 tower welcomes air travelers to Tucson with neon-lit letters and architectural style.

Despite a recent paint job, the factory still sits empty.

The world's largest fully steerable radio telescope.

This rural community has attracted both scientists and techno-refugees due to its federally-mandated lack of technology.

This historic hotel invented the chocolate brownie.

A century-old network of freight tunnels underneath the city's historic business district.

This translucent sculpture represents a quintessential component of New York City's skyline.

Commemorating the spot where the famous scientist fed his pigeons.

A forgotten relic from New York's bygone trolley system hides in plain sight under a bridge.

A small peaceful park and waterfall tucked amid the urban grind of Midtown Manhattan.

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

The original toys that inspired the beloved children's stories are on display at the New York Public Library.

This unmarked and unloved Manhattan subway grate created one of the most iconic images in American cinema.

A replica of a 7th-century church hides in plain sight in the middle of the concrete jungle.

A very classy 1920s-era bar right in Grand Central Station.

The famous facade of Grand Central Terminal hides a regulation tennis court—and it's not the first one.

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

This subterranean oyster house has been the pearl of Grand Central Station since 1913.