The parish encompasses the settlements of St. Levan, Trethewey, Treen (the chief village), and Porthcurno and shares boundaries with the parishes of Sennen in the north-west, St. Buryan in the north-east (with which it has close ties) and is bounded by the sea in the south. It was at one point part of St. Buryan parish. The parish comprises 2,402 acres (10 km2) of land, 3 acres (12,000 m2) of water and 31 acres (130,000 m2) of foreshore.
St. Levan was part of the West Penwith Rural District from 1894 until 1974.
One of the many maps available on A Vision of Britain through Time is one from the Ordnance Survey Series of 1900 illustrating the parish boundaries of Cornwall at the turn of the 20th century. This map blows up to show all the parishes and many of the small villages and hamlets.
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