Lake Maracaibo

Lake Maracaibo is a lagoon in northwestern Venezuela, the largest lake in South America and one of the oldest on Earth, formed 36 million years ago in the Andes Mountains. The fault in the northern section has collapsed and is rich in oil and gas resources. It is Venezuela's main oil producing area and an important fishing and agricultural producing area. Eutrophication caused by oil pollution is a major environmental problem facing the lake. The area around the lake is inhabited by a quarter of the country's population and is also the place with the most frequent lightning on earth. The famous Catatumbo lightning can illuminate nighttime navigation.

Source: Wikipedia