The walls of the iconic dome are hollow and have a secret stairway.

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

The country's oldest continually-operated mini golf course lies hidden in plain sight, eclipsed by one of D.C.'s most popular tourist attractions.

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

A derelict bit of transportation infrastructure hidden in the woods.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

A lovely aquatic park built by a one-armed Civil War veteran who made a fortune from lotuses.

A historic neighborhood church is reborn as a psychedelic arts collective.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

The site of the climactic scene from the classic horror film is now a historic landmark.

More than 2,000 species of tropical plants call this nature preserve and sanctuary home.

A priest with no formal artistic training used basic house paint to create gorgeous religious scenes inside this historic church.

This Hawaiian cattle ranch acts as a museum devoted to the island cowboys that predate the wild west.

Try your hand at old-fashioned coffee growing at this museum devoted to one of the world's most coveted beans.

The air force base preserves its scars from the Japanese attack on Pearl Harbor.

This unusual lava tube spouts seawater during high surf.

This legendary urban waterfall creates a dazzling display of rainbows.

This narrow coastline trail through the dense Kauai wilderness is among the most beautiful and dangerous in the world.

A controversial memorial at the place where Captain Cook met his violent end.

This blowhole is supposedly caused by a trapped monster.

This former luxury resort in Kaua'i is now an abandoned relic.

Submerged lava formations create incredible waterworks.

The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.

This museum of Hawaiian and Polynesian culture is the legacy of the last descendant of the Kamehameha Dynasty.