Harkness Memorial State Park Historic District is located in Waterford, Connecticut. This scenic park features beautiful gardens, walking trails, and a stunning beach along the Long Island Sound. The park is named after the Harkness family, who donated the estate to the state in 1950. The historic district includes the Eolia, a grand mansion built in the early 20th century, which showcases classical architecture and offers a glimpse into the lifestyle of the wealthy during that era. Visitors can explore the estate's grounds, enjoy picnicking, and participate in various recreational activities throughout the year.