Site of the first radio and telephone broadcasting companies in Copenhagen.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

This $3 million model train takes you through Chicago, Seattle, and the thousands of miles in between.

The now-serene site of the largest earthquake ever recorded in North America.

The beginning of the historic Iditarod Trail connecting the Alaskan cities of Seward and Nome.

The king of U.S. high points towers over every other peak on the continent.

Considered by many to be one of the most dangerous highways in Alaska.

In Costa Rica's cloud forest, the roots of a woody ficus create a botanical bridge.

Lankaster is a research and conservation center specializing in orchids and tropical plants, located near the city of Cartago.

Sloth rehabilitation center in the jungle of Costa Rica.

These mysterious ancient stone spheres were created by a civilization lost to time and are now mostly lawn ornaments.

This road in the Great Smoky Mountains was supposed to assuage a displaced community, but ended up a $52 million dead end.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

Some North Carolina Cherokee have been keeping their history alive for decades with a single play.

On a clear afternoon, you can see mountain peaks more than 40 miles away from this clearing in the Pisgah National Forest.

This granite rock face is named for the magnificent reflection that occurs when the sun hits it just right.

This forest school's long history lets today's visitors experience resource management learnings in a beautiful environment.

Who needs fancy modern water slides when this giant North Carolina rock works just as well?

These tree-filled acres are also filled with history, hiking and a celebration of Appalachian crafts.

Visit the site where the original Krispy Kreme doughnut was made back in 1937.

From golden eagles to peregrine falcons, this rehabilitation and education center is a haven for birds of prey.

A giant bronze coil of feces is both a tribute to doggie defecation and a reminder to pick it up.

All of Chicago's wood-paved streets are long gone but two alleys remain.