The show pony of cave systems, Fantastic Caverns manages to live up to its name.

A community of collapsing homes more than a mile out from the Florida coast.

A museum designed by and dedicated to P.T. Barnum in the town where he is buried.

This elaborate Hindu temple is located in a Chicago suburb, but looks like it was transported directly from India.

Community bookshelf of 25-foot-tall book spines.

Home to Hollywood history and a very special salt crystal.

The world's largest military aircraft cemetery.

A Texas-sized particle collider that was abandoned due to its Texas-sized budget.

A recreated Stonehenge stands in a country field, complete with Easter Island moai heads standing as sentries.

An archival collection of over 2,200 case studies which includes human brain specimens and tumor specimens.

A unique attraction and museum dedicated to exploring iconic roadside structures.

A ship that lived many lives under many names is now known merely as the "Ghost Ship."

A stunning, abandoned limestone quarry in southern Indiana provided the stone to erect the Empire State Building.

100-year-old shipwreck you can walk up to at low tide.

The now-abandoned tunnels were built for the transcontinental railroad on the route where the first wagon train entered California.

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

Once defending the city of New Orleans from invasion by sea, this fort faces an uncertain future.

The only Bahá'í house of worship in North America and one of only a handful worldwide.

Shop of curiosities with a dinosaur museum tucked in its basement.

An underground magnet for ever-changing street art.

A secretive collection featuring objects that were designed specifically for U.S. intelligence operations.

The superstar of Cold War nuclear bunkers has been featured in countless films but is now barely operational.

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

A hollow cement depiction of time's inexorable effect on the human body.