A remarkably well-preserved brick chimney from a smelter dating to the 1860s is all that remains of this former mill.

Two well-preserved charcoal kilns survive in a remote part of eastern Nevada.

Beehive charcoal kilns and slag deposits mark this late 19th century camp centered on a smelter.

A picture-perfect town, perfect for blowing up.

Twice a year, visitors can tour the desolate site that birthed the Atomic Age.

Cathedral-like Victorian vaults are hidden within this iconic bridge.

Collection of trolley cars in the woods represent one man's attempt to preserve transportation history.

A collection of bite-sized buildings creates a magical mini village in the Pennsylvania mountains.

Most-visited and most-photographed slot canyon in the American Southwest.

This magnificent natural sandstone bridge is one of the largest in the world and is an iconic symbol for Lake Powell.

The damming of the Colorado River buried an iconic geologic formation before record-breaking drought brought it back.

This natural sandstone bridge hasn't been seen since the 1960s when Lake Powell covered it—until now.

The only natural cave bath in all of Europe.

This covered bridge was used by both Union and Confederate troops during the Battle of Gettysburg in 1863.

Replica of an old Esso filling station, complete with Wayne gravity pump and outhouse.

A monument commemorating the discoverer of radio astronomy.

A journey through the history of medicine throughout the centuries.

Nicknamed the "Grand Canyon of the North," this open-pit mine in Minnesota has a much shorter history.

The crumbling remains of a gold mine that was operational in the 1930s.

In 1954, two enormous earthquakes occurred just minutes apart, resulting in prominent scarps that extend for miles along the range fronts.

Wander through desolate oil fields littered with rigs.

This remote historic museum tells the story of the early telecommunications systems in 1800s Australia.

A place for ship-lovers to watch the passage of freighters traversing the Great Lakes while learning about their history.

A petroleum heritage museum on the site where James Miller Williams dug the first commercial oil well on the continent in 1858.