Simsbury lies in the northern end of the Farmington Valley. The east side of Simsbury is flanked by Talcott Mountain, part of the Metacomet Ridge, a mountainous trap rock ridgeline that stretches from Long Island Sound to nearly the Vermont border. Notable features of the Metacomet Ridge in Simsbury include Heublein Tower, Talcott Mountain State Park, Penwood State Park, and the Tariffville Gorge of the Farmington River. The Metacomet Trail traverses the ridge. At the western foot of the mountain, near the Farmington River, grows the Pinchot Sycamore, the largest tree in Connecticut. Simsbury also has some patches of old growth; Belden Forest, a 40-acre site with public hiking trails near the center of town, was inducted into the Old-Growth Forest Network in October 2019.