But the deepest of the Finger Lakes hides secrets down below. Many have heard what can only be described as cannon shots coming out of nowhere. Known as “Seneca guns” or “Seneca drums,” the phenomenon was thought by the local Seneca Tribe to be the bellowing shouts of Manitou, the Great Spirit, when he was angry. Later, European settlers thought they were hearing ghosts of Seneca warriors still fighting for their land as the ground turned red with blood. It also inspired James Fenimore Cooper to write his short story The Lake Gun, in which he observes: “A sound resembling...