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

Long buried under the 20th-century landscape, this lift lock of the Alexandria Canal is the lone remnant of an ambitious early American transportation project.

The world's only underwater laboratory where "aquanauts" study oceanic life.

This quarter-mile tunnel under the Bluff in Pittsburgh bends at a 45-degree angle.

Headquarters of the world's fourth largest Hasidic sect and the first of many "770s" around the world.

Though illegal, city officials have made an exception for this work of art.

The first railway tunnel to cross the Continental Divide and, at 11,523 feet, was once the highest railroad tunnel in the world.

In 1912, a broken section of the reservoir wall released millions of gallons of water and destroyed many homes downhill.

In one of the hottest parts of the Mojave Desert, shallow bedrock forces the typically dry Mojave River to the surface in this canyon, providing a vital oasis for humans and wildlife.

It’s all about the Benjamins at this Atlanta museum with interactive exhibits.

This mural celebrates the early integration of a New Hampshire baseball team.

A community-funded monument to kindness in the face of life's difficulties.

In the country around Buttonwillow, California, a marker commemorates a revealing moment in the story of a water colony from the fictional Kcymaerxthaere that sought independence.

A whale of a public art display towers atop Juneau's cruise ship dock.

This work of art by Matthew Mazzotta resides in this park dedicated to the first black legislator in Idaho.

Created by Catalan artist Joan Miró in 1978 and made up of 350,000 tiles, this mural is the only large-scale glass mosaic the artist ever created.

The sea urchin sculpture is an unusual commemoration of a New England town's seafaring history.

This metal shop's yard is filled with cutout art including an Eiffel Tower replica and Noah's Arch.

This rooftop sign has been confusing Milwaukee-bound airline passengers for decades.

Known as "The Dome" this is the world's largest open air geodesic dome.

Mining caused an asbestos emergency in this small town.

A tribute to the movie stars who fought to keep Beverly Hills separate from Los Angeles.

Under the shadow of its towering parent tree, a rare specimen of sequoia produces ghostly white leaves.

Boise State's stadium was the first non-green football field in the world.