Lake Nicaragua

     Lake Nicaragua is the 19th largest lake in the world, the largest in Central America. Formed from tectonic activity, the lake is connnected to the Carribean Sea through the San Juan River, even though the lake is much closer to the Pacific Ocean distance-wise. Because of its connection to the Carribean (and therefore the Atlantic), the city of Granada has been an important port. Between the 17th and 19th centuries, Granada was repeatedly attacked by pirates, of which a more detailed account is given here. Though it is a freshwater body, Lake Nicaragua is home to some fish that are usually found in saltwater environments, such as tarpon, sawfish, and even Bull sharks. The sharks in particular will move back and forth between the lake and the Carribean Sea via the San Juan River. A non-native fish, a species of tilapia, has also been introduced into the lake, which could potentially threaten the other, native species of fish already present.
     Lake Nicaragua has also been the site of volcanic activity, which created two main features in the lake. The first feature is the island Ometepe, the largest volcanic island within a freshwater lake in the world. There are still two volcanoes on this island: Maderas and Concepción. Maderas is inactive and is the smaller of the two, while Concepción is still active (last eruption ending as recent as 3/12/11). The second feature is the Solentiname Islands. This is a group of about 35 volcanic islands towards the southern end of Lake Nicaragua. These islands are home to archeological sites, a national monument, and a wildlife refuge; they are also becoming an increasingly popular tourist destination.
    
     The Google image below shows Lake Nicaragua with the main features highlighted.