The Thomas Point Lighthouse is the last remaining, operating screwpile lighthouse on the Chesapeake Bay. The original lighthouse was built on land several miles south of Annapolis in 1825 and was replaced by the present offshore lighthouse which was constructed in 1874. The 250 watt bulb is housed in a Fresnel lens manufactured in Paris over 100 years ago, which magnifies the output to 6,000 candlepower and can be seen for 12 miles, flashing once every 15 seconds. The lighthouse was completely automated in 1986 by the United States Coast Guard following 162 years of being occupied by scores of generations of lighthouse keepers and their families. In 1975 the Thomas Point Lighthouse was included in the National Register of Historic Places which will protect it from future extinction.