Vernal pools are seasonal pools of water that provide habitat for distinctive plants and animals. They are a type of wetland usually devoid of fish, and thus allow the safe development of amphibian and insect species unable to withstand competition or predation by fish. Vernal pools abound in the Groton trail system. An easily reachable one lies across Chicopee Row from Williams Barn where the Mahoney Lane trail skirts a pool just short walk from the trail head. Parking at Williams Barn off of Chicopee Row.