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

The most accurate timepiece in the world.

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

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

A nostalgic bibliographic gem.

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

Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”

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

Before Nixon, "watergate" meant canals.

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

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

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

A portal into the bricked up canal that runs through the heart of Washington D.C.

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

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

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

A celebrity from the late Cretaceous period.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

The national park was once a plantation estate.

The land is home to swimming ponies and a legendary 18th-century treasure.

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

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

This free, take-a-book shop seems like a trick but isn't.

The last holdout of a pre-Civil War rebel who took the matter of slavery into his own hands.