Across the street from the Old Dutch Church [1] is Philipsburg Manor (381 N. Broadway/Rte. 9, 914/631-3992 or 800/448-4007, www.hudsonvalley.org [2], 10 a.m.–6 p.m. Wed.–Mon. Apr.–Oct., weekends only Nov.–Dec., adults $12, seniors $10, students 5–17 $6), a carefully reconstructed 17th- and 18th-century manor house, complete with a working gristmill and small farm.
Once owned by Frederick Philipse of Yonkers [3], the estate is now often jammed with tour buses and groups of schoolkids; of all the Historic Hudson Valley properties, this one is the best for families. Costumed guides describe life in Colonial times as visitors pass through the main stone house, gristmill, Dutch barn, and other buildings.
Links:
[1] http://www.moon.com/destinations/new-york-state/the-hudson-valley/lower-hudson-valley/tarrytown-and-sleepy-hollow/old-dutch-church-and-burying-groun
[2] http://www.hudsonvalley.org
[3] http://www.moon.com/destinations/new-york-state/the-hudson-valley/lower-hudson-valley/yonkers