Calonectris diomedea
Treen Cliff SSSI extends from Porthcurno beach in the west to Penberth Cove in the east. Several rare plant species occur and the site is of particular importance for its maritime heath. Part of the site, Treryn Dinas, is a Scheduled Ancient Monument consisting of a "cliff castle" with four ramparts and ditches, and the Logan Rock was part of the tour of the Land's End area for Victorian tourists. The Porthgwarra to Pordenack Point (SSSI) is noted for its vegetation, 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") and razorbill ("Alca torda"), as well as rarer birds such as Balearic shearwater ("Puffinus mauretanicus") and Cory's shearwater ("Calonectris borealis"). The headland of Tol-pedn (or Gwennap Head) is favoured by birdwatchers and many travel the length and breadth of Britain to track rare seabirds.