The Seven Foot Knoll Light was built in 1855 and is the oldest screw-pile lighthouse in Maryland. It was located atop Seven Foot Knoll in the Chesapeake Bay until it was replaced by a modern navigational aid and relocated to Baltimore's Inner Harbor as a museum exhibit. Location It was initially installed on a rocky shoal called Seven Foot Knoll (at ), in the mouth of the Patapsco River. The northern tidal reach of this river is the Baltimore Harbor, where the now-decommissioned lighthouse has been placed as a museum exhibit. In 1997 the lighthouse was transferred to the Baltimore Maritime Museum (now the Historic Ships in Baltimore museum) and is permanently installed at the south end of Pier 5. Construction Constructed of rolled iron, the lighthouse consists of three main sections. The gallery deck was located above the average high tide waters. The house was the second section, sitting directly atop the gallery deck. This is where the keeper and his family would live. Atop the housing area was the third section of the lighthouse, the light beacon. A 4th order Fresnel lens was housed in the small light compartment. It was visible for . History The first requests for a light came in 1848, with initial appropriations in 1851. Delays in planning and bidding pushed the start of construction to 1854. The house consisted of a cylindrical structure of wrought iron plates, with the ninth pile in the center. Total construction costs came to $43,000 by its completion the following year. Most parts were fabricated in Baltimore at the Murray and Hazelhurst iron foundry. The parts were then shipped to Seven Foot Knoll by boat where they were assembled atop of the screw piles. Ice, the perennial threat to screw-pile structures, caused damage in 1884 and 1894, leading to the piling of of riprap around the piles. The light was automated in 1949, and fell into disrepair, eventually being supplanted by a skeleton tower. In 1988, the lighthouse was removed from Seven Foot Knoll, carried by a 1000 Ton Capacity Shearleg derrick, and placed ashore in Baltimore's Inner Harbor where it was donated to the city. On August 22, 1989 the lighthouse was listed on the National Register of Historic Places. Aided by the Lady Maryland Foundation (now the Living Classrooms Foundation), many members of the Steinhice family descendants worked to restore the structure prior to its re-opening.