Powder House Park, also known as Nathan Tufts Park, is a historic site and public park in Somerville. The park was named after the Powder House, a stone building that was built in 1704 as a windmill and later used to store gunpowder during the American Revolutionary War. The park covers an area of 9.5 acres and features a playground, a picnic area, a basketball court, and a community garden. The park also hosts events and festivals throughout the year.