Cold War intelligence agents monitored communist embassies from an attic in a former pigeon coop.

America's first federal monument.

This rudder is one of the few remnants of a shipyard that once operated on the banks of the Potomac River.

Proto-CIA agents trained with grenades in the sand traps and fired machine guns from the fairways.

A historic arena where the Beatles played their first concert in the U.S.

An oft-overlooked, magically musical monolith that stands majestically between Arlington Cemetery and the Iwo Jima Memorial.

A gift from Japan, 17th-century lantern stands among the cherry trees at D.C.'s Tidal Basin.

The only National Monument ever to go missing for nearly 50 years then resurface in a dump.

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

Largest Roman Catholic church in North America.

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

The Corinthian columns that towered over Abraham Lincoln’s inauguration stand proud.

One of the largest underground systems runs under Canada's largest urban center.

Known as "Toronto's Flatiron."

This whimsical fountain pays tribute to Toronto's four-legged friends.

The best place in the world to buy tinned fish.

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

Look closely and you’ll notice that the color changes a third of the way up the tower.

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

This rare triple-jurisdiction drawbridge passes through Virginia, Maryland, and Washington, D.C.

A downtown park built on top of unclaimed graves.

One of the greatest heroes of the Titanic tragedy came from humble beginnings to this beautiful home.

The spot in the Mile-High City that's exactly 5,280 feet above sea level (at least for now).

Strange red rock formations that have been attributed to a higher power for hundreds of years.