A hidden subterranean installation offers a view of the sky.

A winding path built in secret on the edge of the continent.

Guns that have been defending San Francisco since 1904.

A monument to the love people have for their pets.

A collection of 20th-century automata, penny arcade games, and musical contraptions.

Since 1973, this block has been home to the most concentrated collection of murals in San Francisco.

This enormous banquet-themed artwork honors over 1,000 notable women throughout history.

The miraculous hydrant that saved the Mission District in 1906.

This elaborate tunnel is the first structure composed of cast concrete in the United States.

A mosaic made of materials gathered from this Brooklyn community adorns the walls of this tunnel.

A beautiful geyser under environmental threat.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

Stroll through a wonderland of stupendous moss-covered trees.

This massive redwood tree has a hole in the base big enough to drive through.

One of the most scenic stretches of road in America winds between some of the country's oldest trees.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

Despite a legend that says this highest peak in Oregon was climbed in high heels scores of people have died on its slopes.

Spectacular volcanic cliffs along the Crooked River invite hiking, rock climbing, and photography.

Two mammoth statues inspired by equally tall tales lure tourists to this roadside attraction.

Canyon walls shrouded in ferns.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.

Shakespeare has been brought to life in this open air theater for the better part of a century.

The deepest lake in the United States, and once the site of epic destruction that lives on in legends.

Not-so-fearsome tiny trolls live under this wooden train trestle in Portland.