Lake Matano

Impian Monalisa-Lake Matano (Indonesian: Danau Matano), also known as Matana, is a natural lake in South Sulawesi, Indonesia. It is the deepest lake in Indonesia (ranked by maximum depth), and the 8th deepest lake in the world. It is located at 2°29′7″S 121°20′0″E / -2.48528, 121.33333Coordinates: 2°29′7″S 121°20′0″E / -2.48528, 121.33333.
Lake Matano is home to many species of endemic fish and other animals as well as many plants. The endemic fishes of Matano have been compared to that of the species swarms of the Rift Valley Lakes of Africa. While not as diverse, they are thought to have all arisen from a single ancestor species and diversified into numerous different species, which now fill many of the previously vacant ecological niches.
Despite Lake Matano's remote location, it is the site of Pt. INCO, one of the largest nickel mines in the world, which carries out strip mining in the surrounding rainforest. The company cuts down trees and strips the topsoil to be baked in kilns to extract the nickel. Not only has this led to massive damage to the unique rainforest of the area but it has also had serious detrimental effects on the lake, with far higher sediment loads in the rivers feeding into Lake Matano, often with toxic levels of mining waste. The waters of Lake Matano are exceptionally clear, visibility is good, and many of the fish species are highly dependent on visual cues and colour perception for their mating behaviour. If the sediment washing into the lake continues to increase, the likelihood is that many of these endemic species will be lost.