A throwback train ride transports passengers through one of the lesser-known national parks in the country.

Little did a museum know, they possessed the last-known lunch wagon in existence.

The only surviving prototype for Buckminster Fuller's house of the future.

One of the few working locomotive roundhouses in the United States.

An old railroad grade built for the construction of Hoover Dam is now a recreational trail featuring several tunnels and sweeping views of Lake Mead.

Where a railroad loops under or over itself to rise or drop more than 70 feet in a short distance.

For 150 years one family has been producing the iconic hot sauce on a bayou island made of salt.

The second-largest ceremonial mound in the United States is an artificial hill that is loosely shaped like a pentagon.

An eerie and beautiful group of columns mark the site of a grand mansion lost to time and fire.

A spectacular remnant of an Adler and Sullivan masterpiece that was destroyed in 1972.

On the outskirts of a reborn ghost town, a decaying post office remembers the bad old days.

This rugged area of red rocks and arches is often considered one of the most beautiful places on Earth.

A common entry point to the Griffith Observatory trail holds its own wonders.

This historic hotel on Bathhouse Row in Hot Springs National Park has a storied history of gangsters and baseball greats.

In its day this historic fort held 100 cannons pointed in almost every direction to protect New York.

An 18th-century Spanish watchtower made entirely of seashell and concrete.

This fort down the Potomac from Washington, D.C. was once the only defensive fort protecting the capital.

The last holdout of a pre-Civil War rebel who took the matter of slavery into his own hands.

One of the only Florida forts to remain in the hands of the Union all through the Civil War still stands as a historic stronghold.

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 remnants of the fortress that saved Georgia from the Spanish still stand guard on their swampy island.

A much more welcome kind of snowbird vacationer, manatees camp out in these springs every winter.

The haunting ruins of Jack London's dream house.

After starting as a whimsical tourist attraction that eventually found its way to ruin, these renovated canals offer a lush and exotic locale on the Pacific Coast.