Nicaragua (IPA: /ˌnɪkəˈrɑgwə/) officially the Republic of Nicaragua (Spanish: República de Nicaragua?·i, Spanish pronunciation: [re̞ˈpuβ̞lika ð̞e̞ nikaˈɾaɣ̞wa]), is a representative democratic republic and the largest nation in Central America. It is also the least densely populated with a demographic similar in size to its smaller neighbours. The country is bordered by Honduras to the north and by Costa Rica to the south. The Pacific Ocean lies to the west of the country, while the Caribbean Sea lies to the east. Falling within the tropics, Nicaragua sits 11 degrees north of the Equator, in the Northern Hemisphere. The country's name is derived from Nicarao, the name of the Nahuatl-speaking tribe which inhabited the shores of Lago de Nicaragua before the Spanish conquest of the Americas, and the Spanish word Agua, meaning water, due to the presence of the large lakes Lago de Nicaragua (Cocibolca) and Lago de Managua (Xolotlán), as well as lagoons and rivers in the region. The Nicarao tribe migrated to the area from northern regions after the fall of Teotihuacán, on the advice of their religious leaders. According to tradition, they were to travel south until they encountered a lake with two volcanoes rising out of the waters, and so they stopped when they reached Ometepe, the largest fresh-water volcanic island in the world. Nicaragua occupies a landmass of 129,494 km² - roughly the size of Greece or the state of New York and 1.5 times larger than Portugal. Close to 20% of the country's territory is designated as protected areas such as national parks, nature reserves and biological reserves. The country is bordered by Costa Rica on the south and Honduras on the north, with the Caribbean Sea to the east and the Pacific Ocean to the west. Nicaragua has three distinct geographical regions: the Pacific Lowlands, the North-Central Mountains or highlands and the Atlantic Lowlands.