Lake Willoughby is a deep glacial lake in Westmore in Vermont’s Northeast Kingdom, occupying a steep basin between Mount Pisgah and Mount Hor and often likened to a Norwegian fjord. Known for clear, cold water and exceptional depth, it may be the deepest lake entirely within New England, with some estimates reaching about 340 feet. Its waters flow north into the Saint-François and St. Lawrence systems. Long valued for scenery and recreation, it attracted tourists by steamboat from 1884 into the early 20th century and remains popular for swimming, hiking, ice fishing, and cottage stays. It is also a National Natural Landmark with rare plants, peregrine falcons, and diverse fish and bird life.