Once home to seven different roller coasters, Glen Echo has undergone many transformations since its founding in 1891.

The 72-foot giant escaped confinement in a large patch of mulch only to be reburied in the sandy shores of the Potomac River.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

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

This lovely picnic spot featuring thunderous jet landings is an aircraft spotter’s dream.

The grand marble structure next to the White House is Andrew Carnegie's temple to Pan-American diplomacy.

This mysterious structure by the Washington Monument is a flood barrier designed to protect the White House against rising waters.

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

A tiny monument to the unsuccessful attempt by Thomas Jefferson to place the prime meridian in Washington.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

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

The tallest The Church of Jesus Christ of Latter-day Saints temple in the world soars above the Beltway.

Home to items never before seen by the public.

The sculptor was instructed to add “stallion attributes” to the general's bronze mare.

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

Washington's iconic carousel has a nice piece of Civil Rights history.

A girls' boarding school inspired by the Chicago World's Fair, once abandoned, now restored to strange and scenic glory.

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.

Go take a picture with the inventor of the daguerreotype photographic process.

The longest escalator in the Western Hemisphere takes over three minutes to ride down.

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

D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

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.