Managua is the capital of Nicaragua, the largest country in Central America. The city is situated on the southern shore of Lake Managua (Lake Xolotlán). Nicaragua is famously known as the 'Land of Lakes and Volcanoes' because it is home to two of the largest freshwater lakes in Central America and a chain of 19 active volcanoes. One of these, Lake Nicaragua, is the only freshwater lake in the world to contain sharks (the bull shark, which adapted to the fresh water). Managua itself is built over several fault lines, which led to a devastating earthquake in 1972 that leveled the city center; as a result, the city today lacks a traditional 'downtown' and is spread out over a wide area. A unique cultural quirk of Managua is that many residents do not use street names for addresses, instead giving directions based on proximity to landmarks, even those that no longer exist.