Description Seven Foot Knoll Lighthouse is currently (July 19, 2020) located on Pier Five in Baltimore's Inner Harbor. It's the oldest screw-pile lighthouse in Maryland and was built in 1855. The lighthouse was originally located at the mouth of the Patapsco River before being moved to the Inner Harbor of Baltimore in 1988. Seven Foot Knoll Lighthouse currently serves as an educational tourist attraction and is on the U.S. National Register of Historic Places. Federal Hill is visible in the background of this picture.