The oldest continuously operating fish market in the United States.

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

Home to items never before seen by the public.

The towering figures were created from the cemetery's fallen old-growth trees.

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

This lovely pocket park is one of the most under appreciated in D.C.

A celebrity from the late Cretaceous period.

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

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

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

A much-maligned monument to teetotalism.

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

Light bulbs, scrap wood, and tinfoil comprise this homemade throne of the gods.

An easily overlooked memorial to a Ukrainian famine-genocide that killed over 4 million people.

The privately owned cemetery that holds room for Washington's finest when they step down from life.

Home to a vast and influential collection of Shakespeareana.

A Spiritualist house of worship where believers communicate with the dead in the spirit world.

Live data is transmitted from the Atlantic coast to instantly recreate the ocean waves in this fountain at the NOAA headquarters.

This stunning blue and gold room changed cities twice before becoming part of the Smithsonian.

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

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

A historic estate packed with George Washington's heirlooms, and its own nuclear bunker.

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

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