An artsy hidden staircase leads to breathtaking views of San Francisco.

A terrific purveyor of natural history objects and curios.

During prohibition, corrupt city officials ran drinking dens under the streets of Downtown Los Angeles.

A huge musical instrument played by the ocean.

A trailblazing sovereign nation tucked in the American state of Wisconsin.

Literally a million fascinating cartographic artifacts are held in this sprawling university collection.

A house and yard adorned with bizarre concrete sculptures in a Milwaukee suburb.

An off-the-beaten-path place to literally hang beneath Milwaukee's Holton Street Bridge.

Six tiny houses built for working class people form the largest intentional cluster of Wright homes anywhere.

Robots, lasers, and whoopee cushions, oh my!

Cemetery featuring rare glass-fronted columbarium.

This sprawling mini-golf empire is an impressive testament to a disappearing attraction.

Medical museum focused on antique anesthesiology equipment.

A hidden grotto on the grounds of the Kane County Government Center.

The face of a woman pushes its way through the earth.

What was once a true peninsula has now been filled in, causing the water to recede and leaving many streetside "waterfronts" and landlocked "islands."

Silverware in the sidewalk outside a grocery store cements this neighborhood’s Italian culinary history.

This popular Boston haunt is reminiscent of a time gone by, when slow cafes and sweet-smelling smoke wafting from patios was the norm.

This area was once known for being a lawless haven for rough-and-tumble sailors, earning the maritime-themed nickname "the black sea."

Sacks of potatoes, made of cast stone, mark where the iconic potato sheds once stood along the river.

The remnants of a Gilded Age elegance preserved in the middle of a stark modern tower.

A more than 260-year-old crypt built on Boston's oldest English burial ground.

A mysterious stone embedded at the base of a historic Boston building.

No one messes with the Massachusetts sacred cod, not this time...