English: Taal Lake is a freshwater lake in the province of Batangas, on the island of Luzon, Philippines. The lake is situated within a caldera formed by very large eruptions between 500,000 and 100,000 years ago. The active Taal Volcano, which is the one responsible for the lake's sulfuric content, lies on an island in the center of the lake, called Volcano Island. In addition, there is a crater lake on Volcano Island, which is in Lake Taal, which in turn is on Luzon (an island). That crater lake is the world's largest lake on an island in a lake on an island. The small island on the far side of the lake is called Vulcan Point.