A prominent hill in Hannibal, originally known as Holliday's Hill.  Mark Twain named the fictional location from a place in Cardiff, Wales that reminded him of Holliday's Hill.  It figures in The Adventures of Tom Sawyer and Adventures of Huckleberry Finn.  It stands about 300 feet above the Mississippi River, the southern end of a long escarpment that parallels the river.  Rasmussen reports that this is the location from which Sam and a friend rolled a boulder down the hill and through a cooper's shed in town.