Federal Hill is a vibrant and popular neighborhood in Baltimore that lies just to the south of the city's central business district. Many of the structures are included in the Federal Hill Historic District, listed on the National Register of Historic Places in 1970. From early in the history of the city, the hill was a public gathering place and civic treasure. The hill itself was given the name in 1789 after serving as the location for the end of a parade and a following civic celebration of the ratification of the new "Federal" constitution of the United States of America. For much of the early history of Baltimore, the hill was known as Signal Hill because it was home to a maritime observatory serving the merchant and shipping interests of the city by observing the sailing of ships up the Patapsco River and signaling their impending arrival to downtown.