The Burin Peninsula is a peninsula located on the south coast of the island of Newfoundland in the province of Newfoundland and Labrador. Marystown is the largest population centre on the peninsula. The Burin Peninsula extends to the southwest from the main island of Newfoundland, separating Fortune Bay to the west from Placentia Bay to the east. It …The Burin Peninsula is a peninsula located on the south coast of the island of Newfoundland in the province of Newfoundland and Labrador. Marystown is the largest population centre on the peninsula. The Burin Peninsula extends to the southwest from the main island of Newfoundland, separating Fortune Bay to the west from Placentia Bay to the east. It measures approximately 130 km in length and between 15 and 30 kilometres in width. It is connected by a 30 km wide isthmus between Terrenceville and Monkstown.