Deemed one of the island’s cleaner bodies of water by the Massachusetts Estuaries Project, Sesachacha Pond is Nantucket’s largest kettle pond and is probably the deepest pond on the island at 43 feet. Its northeast and southeast shores are sparsely populated with seasonal houses. Most of Sesachacha Pond is surrounded by conservation land owned by the Massachusetts Audubon Society called the Sesachacha Heathlands Wildlife Sanctuary.