Prone to disastrous fires, the city of San Francisco has the Guardian, a fireboat gifted by residents, to watch over them from the bay.

The neighborhood church casts a breast-shaped shadow that locals have come to call the “two o’clock titty.”

A monument to the love people have for their pets.

Once the largest windmill outside of Holland, with enormous 114 foot sails.

Once close to extinction, there is no shortage of elephant seals on the beaches of Año Nuevo State Park.

A New England-style lighthouse along California's beautiful Highway 1 gets a re-do.

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

A huge musical instrument played by the ocean.

A tunnel with windows, so you don't miss out on the impressive views.

The unusual patterns in this rock formation result from two distinct modes of weathering.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

This isolated outpost was once the only place to cross the Colorado River for hundreds of miles.

A sharp bend in a dramatic river canyon cut through red rocks.

An arsenic-filled pool in the Grand Canyon takes on the appearance of a giant, overflowing pumpkin.

One of Vietnam's most iconic landmarks was built by Japanese traders and is now in danger of sinking.

In a small Japanese garden off a busy Denver street, a memorial to a brave, principled politician.

This massive home was constructed by one of the greatest conservationists in Colorado history.

Ancient artists in the middle of nowhere.

Unexplained bald patches in the landscape grow and recede over time, as though they are somehow alive.

This "dead marsh" sits among the largest sand dunes in the world, a forest frozen in time.

A desert that rolls right up to the ocean, where it's so dry animals live off the fog.

Thomas Jefferson's estate is home to hundreds of varieties of historic fruits and vegetables.

This hidden oasis features a stunning view of the Hudson River and the Palisades from a castle-like museum.

A beautiful example of 18th-century engineering still standing tall.