St Nectan&#39;s Glen, Tintagel, Cornwall. One of Cornwall’s most sacred sites, St. Nectan’s waterfall is in a designated Site of Special Scientific Interest (SSSI).  It has been described as amongst the ten most important spiritual sites in the  country.  A place of outstanding natural beauty.  The magic and tranquility of St. Nectan’s Kieve are unique.  The Kieve is a potent symbol of Mother Earth.