Urban Forestry Center OutdoorsWebsite » 45 Elwyn RoadPortsmouth, NH 03801-8710 (603) 431-6774 The 182-acre Urban Forestry Center offers a series of self-guided trails for walking, cross-country skiing, and snowshoeing Hours:Office - 8 a.m.-4 p.m. M-F; Trails - 7 a.m. to 8 p.m. dailySeason:Spring, Fall, Winter