Just a half-hour upriver from the 21st-century pace of New York City, this eye-opening agricultural estate is a jarring retreat to the late 17th and early 18th centuries. The bridge across the millpond of this Colonial farm and water-powered gristmill transports visitors to a complicated time in history, when this estate functioned as one of the largest slave plantations in the North -- a shock to those who associate slavery only with the South. Organizers use that history to educate and place the estate, the entire Hudson Valley, and the influence of African culture in a historical context. Live demonstrations and scripted vignettes by interpreters in period dress bring to life the Colonial period, re-creating the lives of the single caretaker and 23 skilled slaves who lived and worked at this provision plantation. Frederick Philipse made his fortune in shipping and export to the West Indies, commerce that included the human slave trade. The large original manor house dates from 1685, when Philipse's landholdings in the area totaled more than 50,000 acres. When he died a bachelor, he left a 50-page inventory of his belongings, including the names of all his slaves, testimony to his extraordinary wealth. The site still functions as a working farm, with horses and sheep, wool spinning, milling of flour, and harvesting of rye. A great, educational outing for families (children will especially enjoy the special "Hands on the House" tours, featuring interactive "touch rooms," held on weekends at 11:30am, 2:30, and 4pm); allow a couple of hours.