Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

The Sun King's military models, saved from the Louvre.

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

One critic described it as "middle Mussolini, early Ramses, and late Neiman-Marcus." Another called it an architectural "natural disaster."

Corn-inthian columns with a uniquely American take on neoclassical architecture.

This statue of the "father of television" stands prominently in the United States Capitol.

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

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

Railroad officials in the early 1900s sought to spare travelers the sight of Roman soldiers’ private parts.

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

One of the three perfect vellum copies of this historic book known to exist is on display in a specially-designed case.

Washington's top-secret Cold War-era doomsday communications tower is located in a small neighborhood park.

The only Civil War battle in Washington D.C. took place near this highest natural point in the city.

The school tested mustard gas for the U.S. Army during World War I.

These unusual rooms on wheels are holdovers from the 1960s.

Bubbling up from deep underground is the warm crystal clear water that fills the Warm Springs Pools, America's oldest spa.

America's post-nuclear-attack chambers of Congress.

One of the oldest standing structures in Montgomery County, Maryland.

The bridge's highly-contested plaque (once again) honors Confederate President Jefferson Davis.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

This campus chapel is Robert E. Lee's final resting place and a topic of debate about the legacy of the Civil War.

The final home of the most famous horse of the American Civil War.

The only recreation of William Shakespeare's indoor playhouse.

The only ski tunnel in North America provides easy access to amazing snow and beautiful views.