Mount Monadnock, or Grand Monadnock, is a mountain in the towns of Jaffrey and Dublin, New Hampshire. It is the most prominent mountain peak in southern New Hampshire and is the highest point in Cheshire County. It lies southwest of Concord and northwest of Boston. At , Mount Monadnock is nearly higher than any other mountain peak within and rises above the surrounding landscape. It is known for being featured in the writings of Ralph Waldo Emerson and Henry David Thoreau.