Gillette Castle State Park is located in East Haddam, Connecticut in the United States. Sitting high above the Connecticut River, the castle was originally a private residence commissioned and designed by William Gillette, an American actor who is most famous for his portrayal of Sherlock Holmes on stage. After Gillette died, with no wife or children, his will precluded the possession of his castle by any "blithering sap-head who has no conception of where he is or with what surrounded".