Gillette Castle State Park straddles the towns of East Haddam and Lyme, Connecticut in the United States, sitting high above the Connecticut River. The castle was designed and built by William Gillette, an American actor most famous for his portrayal of Sherlock Holmes on stage. Gillette lived here from 1919 until his death in 1937. The State of Connecticut purchased the property in 1943 for $29,000.