Restoration work on a last-of-its-kind Chesapeake Bay lighthouse is progressing, but more money is needed to get the job done.

The Thomas Point Shoal lighthouse was built in 1875 off the shore of Annapolis, Maryland. And in 1999, it was designated a National Historic Landmark.

“It is the last surviving screw-pile lighthouse in the world in its original location, still being used for navigational purposes,” said John Potvin, the lighthouse’s preservation foreman and member of the U.S. Lighthouse Society. “At one time, there were 40 of these screw-pile lighthouses on the Bay.”

The structure, which is also considered to be Maryland’s most recognizable lighthouse, was purchased in 2004 by the City of Annapolis, Anne Arundel County, the Annapolis Maritime Museum and the U.S. Lighthouse Society.