Guanajuato (Spanish pronunciation: [gwanaˈxwato]) is a municipality in central Mexico and the capital of the state of the same name. It is part of the macroregion of the Bajío. It is located in a narrow valley, which makes its streets narrow and winding. Most are alleys that cars cannot pass through, and some are long sets of stairs up the mountainsides. Many of the city's thoroughfares are partially or fully underground. The historic center has numerous small plazas and colonial-era mansions, churches, and civil constructions built using pink or green sandstone. The city historic center and the adjacent mines were proclaimed a World Heritage Site by UNESCO in 1988. The growth of Guanajuato resulted from the abundantly available minerals in the mountains surrounding it. Its mines were among the most important during the European colonization of America (along with Zacatecas also in Mexico, Potosí in Bolivia and Ouro Preto in Brazil). One of the mines, La Valenciana, accounted for two-thirds of the world's silver production at the height of its production. The city is home to the Mummy Museum, which contains naturally mummified bodies that were found in the municipal cemetery between the mid 19th and 20th centuries. It is also home to the Festival Internacional Cervantino, which invites artists and performers from all over the world as well as Mexico. Guanajuato was the site of the first battle of the Mexican War of Independence between newly assimilated Mexican insurgent warriors and royalist troops at the Alhóndiga de Granaditas.