During his career as an actor, William Gillette portrayed world-renowned character Sherlock Holmes in more than 1,300 performances. His career as a playwright and actor afforded him the opportunity to purchase a 184-acre estate, where he also built a twenty-four-room medieval-style castle. Overlooking the Connecticut River, Gillette's castle was complete with spy mirrors, sliding furniture, hidden rooms and a three-mile quarter-scale railroad. Since becoming a state park in 1943, it has evolved into one of Connecticut's most popular tourist attractions. Writer and award-winning journalist Erik Ofgang examines the history of an iconic structure and Gillette's life and role in the evolution of Sherlock Holmes.