Monadnock Mountain, or Mount Monadnock, is an isolated 3,148-foot peak in Lemington in Vermont’s Northeast Kingdom, rising above the Connecticut River valley and facing east toward Colebrook, New Hampshire. Its summit offers wide views, aided by an old fire tower that still stands at the top; in clear weather the panorama extends beyond nearby Vermont and New Hampshire hills to Maine and north toward Quebec. The principal ascent is the Monadnock Mountain Trail on the eastern slope, a 2.5-mile climb with about 2,130 feet of elevation gain from Vermont Route 102. Near the mountain’s base lies the abandoned Norton Mine, a former gold mine whose entrance is now blocked.