Viking settlement in Newfoundland — the only confirmed pre-Columbian European presence in the Americas. Inscribed 1978 (founding-12 site).
From Wikipedia
L'Anse aux Meadows is an archaeological site, first excavated in the 1960s, of a Norse settlement dating to approximately 1,000 years ago. The site is located near St. Anthony on the northernmost tip of the island of Newfoundland in the Canadian province of Newfoundland and Labrador.