Founded by the Spaniards as Santiago de los Caballeros de Leon, the city of Leon has a complex history filled with highs and lows. After an eruption of the Momotombo volcano, the city was abandoned in 1610. The ruins of the abandoned city are known as "Leon Viejo" and were excavated in 1960. In 2000, León Viejo was declared an UNESCO World Heritage Site. (CINDY MILLER HOPKINS—ALAMY)