Situated on a coastal plain facing the Atlantic Ocean, Sligo is located on low gravel hills on the banks of the Garavogue River between Lough Gill and the estuary of the Garavogue river leading to Sligo Bay. The town is surrounded on three sides by an arc of mountains, with the Ox Mountain ridges of Slieve Daeane and Killery Mountain to the southeast bordering Lough Gill. The flat topped limestone plateaux of Cope's, Keelogyboy and Castlegal Mountains to the north and northeast and the singular hill of Knocknarea with its Neolithic cairn to the west and the distinctive high plateau of Benbulben to the north.