This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

Abandoned railway line circling the city of Paris.

On the Fourth of July this area will transform into a Pompeii-like storm of falling embers and ash.

A 1,100-ton train fell through the floor in 1953. Workers got it patched up in just 72 hours.

An overlooked memorial honoring the local Washington residents who died in World War I.

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

One of the most influential presidents in U.S. history wanted only this plain, elegant monument as his lasting memorial.

This seemingly out-of-place gas station by the Watergate hotel was once described as the most expensive gas station in the world.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

This unacceptably tall building was the real reason for Washington, D.C.'s skyscraper ban.

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

An unassuming, powerful monument north of the U.S. Capitol bears witness to the resilience of Japanese Americans during a time of grave injustice.

Decades before the scandal, this staircase on the river was a literal "water gate."

Largest Roman Catholic church in North America.

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

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

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

A lovely aquatic park built by a one-armed Civil War veteran who made a fortune from lotuses.

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

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

Home to items never before seen by the public.

The United States Capitol's former columns still stand.