Fort Wetherill Fort Wetherill is a former Coast Artillery fort that occupies the southern portion of the eastern tip of Conanicut Island , located in Jamestown , Rhode Island . The fort sits atop high granite cliffs , overlooking the entrance to Narragansett Bay . Fort Dumpling , dating from the Revolutionary War , used to occupy a small site within Fort Wetherill . The fort was deactivated and turned over to the State of Rhode Island after World War II and is now operated as Fort Wetherill State Park , a reservation . Today the park is managed by the Rhode Island Department of Environmental Management . Early History . In the 18th Century , an earthwork fortification was constructed at the site of Dumpling Rock , which overlooks the strategic East Passage toward Newport . This old fort was occupied by American , British and French forces for various periods of time during the Revolutionary War . The British abandoned the fort at Dumpling Rock in 1779 when they evacuated Newport . In 1798 construction was started on a permanent fortification at Dumpling Rock under the supervision of Major Louis Tousard of the Army Corps of Engineers . This fort was officially called Fort Louis and , later , Fort Brown ( after Major General Jacob Brown , commanding general of the United States Army ) but was commonly called Fort Dumpling throughout its existence . Fort Dumpling was in the form of an oval stone tower and was frequently used as an artistic motif and a place for social outings . Modern History . In 1899 , during the Endicott period of coastal fortification , the U . S . government purchased additional land and built Fort Wetherill at the southeast tip of Conanicut Island ( the island now occupied by the Town of Jamestown ) . The fort was named for Captain Alexander Macomb Wetherill , a Jamestown native who was killed in action during the Battle of San Juan Hill . Fort Dumpling was destroyed in the process of building the new fort , which featured numerous concrete emplacements for 20th Century breach - loading , rifled coast artillery pieces . In 1901 , Battery Varnum , mounting two 12 - inch guns on barbette carriages and situated in the far southeast corner of the fort , was the first modern battery to be completed . By 1910 , the other six batteries in the fort ' s pre - World War II arsenal had been brought into service . Although several of these batteries are now overgrown with brush , they offer what is perhaps the longest linear concrete gun line in the coast defenses of New England . During World War I , the fort was garrisoned by five companies of Coast Artillery from the Rhode Island National Guard . After the war , Fort Wetherill reverted to " caretaker status , " with only a single Coast Artillery sergeant assigned to watch over it and other nearby facilities . Fort Wetherill was reactivated by the U . S . Army in September 1940 as a major part of the harbor defenses of Narragansett Bay and new barracks were built to house the 243rd Coast Artillery Regiment and its 1 , 200 soldiers . The fort also functioned in the year before World War II as a military training facility , and late in the war as a training center for German prisoners of war . In 1946 , the U . S . military ceased operations at Fort Wetherill , and the site remained abandoned for the quarter century that followed . The State of Rhode Island officially acquired the fort on August 16 , 1972 , and reconfigured the site for public use as a state park . In 1972 the site was also added to the National Register of Historic Places . The park continues to attract visitors with a variety of modern recreational uses . The property offers walking trails through wooded areas and along the rocky coast , and is a popular destination for scuba diving . Spectacular ocean views draw seasonal visitors from all over who come to observe special events such as the Tall Ships America and annual fireworks displays from atop the old fort . Another distinctive feature of the fort is its surviving buildings and tramway system that were once used in the operation of the submarine mining operation that was run from the fort during World War I and World War II . During World War II , some 300 mines were planted on the east and west sides of Conanicut Island , protecting the approaches to Newport , and almost all of these were maintained from the Mine Wharf at Fort Wetherill . The image at left shows the old mine storehouse , one of the best preserved in the United States , with the remains of the tram tracks that used to carry the massive mines in and out its front door . Mine launches would tie up at the nearby wharf , load the mines that were to be laid , transport them out into the inlet , and lay them , together with their electric cables . Then , when these mines needed to be taken in , they were ferried back to the wharf and transported on the tramway to the various service buildings . A dual mine observation station sat atop the hill between the storehouse and Battery Varnum . Spotters manned this station ( and others scattered around the harbor defenses ) and could locate enemy ships approaching the minefields , signaling to the operators in the mining casemate when a given mine was to be electrically detonated . Modern Armament . Beginning in the early 20th Century , the seven major concrete gun batteries listed below were built and armed at Fort Wetherill . In addition , Anti - Motor Torpedo Boat ( AMTB ) Battery 923 , consisting of two 90mm guns , was built upon platforms that remained from an earlier antiaircraft gun battery . Only the first two batteries listed below ( plus the World War II AMTB battery ) were operational during World War II . Current Uses . After being acquired by the state of Rhode Island , Fort Wetherill quickly became a location for great sight seeing and other activities . It is popular to view the Tall Ships America event that takes place in Narragansett Bay every summer , as well as The America ' s Cup sailing races . Other activities that are popular for the area include scuba diving , bird watching , fishing , trail walking , dog walking , and graffiti art . The park offers ample parking facilities , public restrooms , trash / dog waste bags , and picnic tables . Jumping off the rocks at Fort Wetherill is prohibited , along with the consumption of alcohol . The park has no entrance fee and can be accessed between sunrise and sunset .