A historic lighthouse located in Baltimore, Maryland, USA. Built in 1856, it is the oldest existing spiral pile lighthouse in the Chesapeake Bay area. Originally built at the entrance of the Patapsco River in Chesapeake Bay, it was later relocated to its current location and became part of the Baltimore Maritime Museum. The design is unique, entirely made of iron and featuring a circular design, which is unparalleled among the spiral pile lighthouses in the Chesapeake Bay area. It is also one of the earliest lighthouses to use prefabricated components, which allows certain parts to be transported to the site and quickly assembled. It is an important symbol of American maritime history.