Gwennap Head identified steamships were wrecked, stranded or sank in the area. There have been none since 1923. The navigation markers feature as "the Cones of Runnel" in Hammond Innes's 1940 thriller "The Trojan Horse". Gwennap Head is part of the Porthgwarra to Pordenack Point Site of Special Scientific Interest (SSSI) designated for its vegetation of waved maritime heath, and for being of considerable ornithological interest; especially for passage migrants. It is renowned for its relative abundance of passing marine bird species with many common species such as northern gannet ("Morus bassanus"), Manx shearwater ("Puffinus puffinus"), common guillemot, ("Uria aalge"), razorbill ("Alca
Gwennap Head 15 October each year and most of the recording was by volunteers who spent up to twelve hours a day on seawatch. The main targeted species were Balearic shearwater ("Puffinus mauretanicus") and basking shark, along with the ocean sunfish (or common mola). Marine mammals such as whales, dolphins and grey seal ("Halichoerus grypus") were additional main targets. During a seawatch on 28 August 2015 a red-billed tropicbird ("Phaethon aethereus") was seen over the Runnel Stone, a bird that usually frequents tropical areas. Gwennap Head is part of the Land’s End granite massif with shallow, free-draining and acidic soils. The dominant