This colonial mansion has been home to a staggering number of American historic figures.

A museum dedicated to the strange and extravagant costumes and memorabilia of the mummers, a tradition older than Philadelphia itself.

The land is home to swimming ponies and a legendary 18th-century treasure.

A unique marker erected during the 18th century.

A desiccated merman and a walrus penis bone are among the oddities in this eclectic collection of shipwreck treasures.

This one-room schoolhouse played a significant role in the education of Black children for almost 100 years.

This 1830s store is believed to be the site of Harriet Tubman's first stand.

The stone marker that Mason and Dixon placed at the eastern end of the famous north-south border they surveyed.

Once a lonely sentinel on the edge of the Great Plains, this rebuilt trading fort offers a glimpse of life on the Santa Fe Trail.

The scene of one of the darkest moments in American labor history has been left essentially untouched since the tragedy.

The notorious headquarters of a corrupt political machine.

The first declared National Monument in the United States.

Largest gathering of hobos in the country has been meeting annually since 1900.

The only retired U.S. nuclear missile silo that is open to the public.

The only road through the heart of Glacier National Park.

Native Americans built this circle of stones, which was used to predict astronomical events.

The remote outlaw hideout of Jesse James, Butch Cassidy, and the Sundance Kid.

A popular rock that acted as a waymarker for American pioneers.

Long before guestbooks and hotels, frontier travelers signed their names on this rock face.

This Colorado fire station has been in continuous operation for more than a century.

The largest source of fossilized insects anywhere.

These faux-cliff dwellings allow visitors to climb around on a replica archaeological site.

This erect, phallic geological spire wasn't always named so domestically.

An experimental, automotive replica of Stonehenge.