The ruins of a Duke's bucolic dream, where camels once roamed alongside "Dutch" windmills and faux-Italian vineyards.

The history of radiation is on safe display at the foot of a radiation science laboratory.

A subterranean shelter remains intact under a busy Paris railway station.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

Indents in the pavement are all that remain from a grisly death machine in Paris.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

The oldest stone house in Paris was built by its most famous alchemist.

During the solar phenomenon "Lahaina Noon" this bendy, curvy sculpture forms a perfectly circular shadow on the ground.

Climbing this abandoned railway leads to breathtaking vistas of O‘ahu.

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

What remains of the summer palace of King Kamehameha III.

The site of a minor battle might have been forgotten if not for one participant’s famous family and the death of a respected warrior.

This marker identifies the location where three states converge.

A unique arch graces the Dolores River Canyon near the Hanging Flume.

This now-abandoned outcrop is an important Native American spiritual site, overtaken by European settlers and mining pollution.

The site of a defunct mill, that once supplied marble for the construction of the Lincoln Memorial.

The decaying ruins of a failed mining company’s water diversion project cling to the side of a desert canyon.

A museum of natural history, Edwin Carter's original log cabin home and workshop houses taxidermy specimens.

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.

Open-air cremations in Colorado's self-proclaimed spiritual mecca.

The site of the "Bone Wars" between two rival paleontologists during the dinosaur rush of the 19th century.

An antique narrow gauge railway line still running through the Colorado and New Mexico mountains.

This sidewalk tribute honors Colorado's great culinary creation.

A stark reminder of the huge nuclear weapons plant that once stood on the site and its effect on the surrounding area.