The longest-covered bridge in the state of Maryland.

This refurbished gas station is one of the oldest in Texas, located on the original Route 66.

Public opinion is still divided on this enormous sculpture in front of Baltimore's Penn Station.

An homage to Jackie Gleason's bus-driving character from 'The Honeymooners.'

Inside this library, the history of Los Angeles is retold through a mural.

Ruins of the original wooden flume that carried water to Virginia City are still visible high on the Virginia Range.

One of the best-preserved remains of "Tokyo's lost rivers."

These sculptures were designed to beautify this neighborhood when it was established in the 1940s.

The only subway station in the city that still makes use of gap fillers.

The oldest private residence in New York City.

This narrow coastline trail through the dense Kauai wilderness is among the most beautiful and dangerous in the world.

A once-glowing grotto at the bottom of Waikapalae Wet Cave.

Now a pedestrian bridge, this was once part of a narrow-gauge railroad that ran along the east coast of Kauai.

This former luxury resort in Kaua'i is now an abandoned relic.

This ruined fort and statue are a testament to the last king of Kaua‘i’s savvy diplomacy skills, which briefly brought Russians to Hawai‘i.

Gold Rush-era tombstones line the park's paths.

Visible below the waves are memorials to the city's Gold Rush dead.

This restaurant features Native American foods from across the country.

A massive ultra-modern church presents a science-fiction view of Catholicism's inclusive future.

A restored 1920s cascade stairway provides one of the best views of Oakland's Lake Merritt.

Bonsai garden in Oakland is curated by the first non-Japanese female bonsai master in the United States.

Not merely a museum – but a whirring powerhouse that offers a subterranean peek into the heart and soul of cable car operations.

Early prototype for Frank Lloyd Wright's Guggenheim.

This teeny-tiny park built by a San Francisco man in 1962 is mostly stairs.