Located on the Southwest Waterfront of Washington, D.C., just under the shadow of Interstate 395, the Maine Avenue Fish Market stands as a cultural relic popular with locals but unknown to many of the tourists who flock to the monuments and museums just five blocks north.

There are over ten stores, each with a specialty. The Maine Avenue Fish Market is open each day of the week, but the largest selection of fish is on display Friday evening through Sunday.

A multitude of fresh seafood is sold on floating barges that line the pier along Water Street. These barges, which rise and fall with the tide, are a tribute to an old tradition dating back to the Civil War. For years, fishmongers would navigate theirs once a week down the Potomac to the Chesapeake.

There, they would purchase seafood from the watermen and head back to the Washington, DC wharf. In 1961, refrigerated trucks became more efficient to bring the catch from the Eastern Shore and the “buy boats” were permanently docked and later replaced by the steel barges which exist today.

According to wikipedia