This morbid, delightful curiosity shop offers everything from animal bones to human teeth.

The twin towers in this Chicago fountain use 50 foot tall video screens to spit on people.

Each of these gorgeous, intricately decorated rooms is painstakingly crafted to the scale of 1 inch: 1 foot.

A monument to the art of slicing people open.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

This elaborate Hindu temple is located in a Chicago suburb, but looks like it was transported directly from India.

Arguably the best example of an authentic Dutch windmill in the United States, rivaling its counterparts in the Netherlands.

A haunting statue called "Eternal Silence" has quite the reputation among visitors with active imaginations.

People escaping slavery may have hidden inside a corpse vault.

A hoard of sky catalogs, astrophysical journals, even the works of Galileo and Copernicus.

The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.

The Byzantine, pre-Columbian, and medieval art at this stately mansion are some of the most under-appreciated collections in D.C.

You could be standing at the site of one of D.C.'s most fatal tragedies and not even know it.

This sandwich shop has a century-old elevator behind a sheet of plexiglass.

A historic neighborhood church is reborn as a psychedelic arts collective.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

The walls of the iconic dome are hollow and have a secret stairway.

A derelict bit of transportation infrastructure hidden in the woods.

During the Industrial Revolution this “Temple of Invention” was full of intricate miniature machines and gadgets.

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

A wondrous old library overlooking the nation's capital.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.