Mar Dulce, “Sweet Sea,” seems an odd nickname for Lake Nicaragua when you realize that it’s the only lake in the world to sport freshwater sharks. In the 17th century pirates also braved the lake waters, not one, but three times to sack the port city of Granada. The lake, also known as Lago Granada, Lake Cocibolca, Gran Lago, Gran Lago Dulce or Lake Granada, , is approximately 99 miles (160 km) long, 45 miles (72 km) wide and 84 feet (26 meters) deep.

Lake Nicaragua is the largest lake in Central America and the second largest in Latin America (after Lake Titicaca). It is connected to Lake Managua by the Tipitapa River and to the Caribbean Sea by the San Juan River. Historically, such connections make Granada an Atlantic port, even though the city is closer to the Pacific. Under a 1884 treaty between the United States of America and Nicaragua, plans were made to build a canal linking the Caribbean Sea and the Pacific Ocean. However, due to political unrest, construction was halted in 1893 and the once planned Nicaragua Canal was moved to Panama.

The lake waters, as well as being home to freshwater sharks, contain other fish that are usually only found in the salty ocean, such as swordfish, tarpon and tuna. One of the current theories is that their ancestors were trapped in Lake Nicaragua by lava flow that blocked access to the Pacific Ocean.

The lava didn’t stop Henry Morgan in his pirate days (later appointed Lieutenant Governor of Jamaica) from canoeing in from the Rio San Juan and sacking Granada in 1665 and two more times before 1670.

Lake Nicaragua has hundreds of islands, including an archipelago of over 350 tiny islets near Granada, all with lush plant and wildlife. People living on these islands fish and farm crops such as bananas, coffee, tobacco, wheat and sesame. On the island of Zapatera pre-Colombian statues were found and are now exhibited in the museum of the Convent of Saint Francis of Granada. Further south, you’ll be able to find the lake’s largest island, Ometepe, which was formed by the lava flow of two volcanoes: Concepción, which is still active, and now-dormant Maderas. Both volcanoes can be climbed, although Volcán Concepción is more physically demanding. Visitors can stay in Moyogalpa or Altagracia and get there by ferry from Granada or San Jorge.