Troisième lac du Castor is a Lake located in Notre-Dame-de-la-Merci; Matawinie, Quebec and has an elevation of 411 meters.

• Latitude: 46° 15' 50'' North   (decimal: 46.2638888)
• Longitude: 73° 57' 16'' West   (decimal: -73.9544444)
• Topography Feature Category: Lake
• Geographical Feature: Lac
• Canadian Province/Territory: Quebec
• Elevation: 411 meters
• Location: Notre-Dame-de-la-Merci; Matawinie
• Atlas of Canada Locator Map: Troisième lac du Castor
• GPS Coordinate Locator Map: Troisième lac du Castor Lat/Long