Lake Grevelingen is a large, brackish lake located in the southwestern part of the Netherlands. It was formed in the 1970s when the construction of the Deltaworks separated it from the North Sea. The lake is known for its diverse marine life and is a popular destination for water sports, including sailing, windsurfing, and diving. The lake is surrounded by several towns, including Burgh-Haamstede and Ouddorp, which offer amenities for visitors. Its unique ecosystem supports various species of fish and birds, making it an important area for both recreation and conservation efforts.