parties, founded in 1848 and 1849, are two of the oldest surviving political parties in the Americas.
Colombia is ethnically diverse. The interaction between descendants of the original native inhabitants, Spanish colonists, Africans brought as slaves and twentieth-century immigrants from Europe and the Middle East has produced a varied cultural heritage. This has also been influenced by Colombia's varied geography. The majority of the urban centres are located in the highlands of the Andes mountains, but Colombian territory also encompasses Amazon rainforest, tropical grassland and both Caribbean and Pacific coastlines. Ecologically, Colombia is one of the world's 17 megadiverse countries, and is considered the most megadiverse per square kilometer.
Tensions between political parties have frequently erupted into violence, most notably in the Thousand Days War (1899–1902) and La Violencia, beginning in 1948. Since the 1960s, government forces, left-wing insurgents and right-wing paramilitaries have been engaged in the continent's longest-running armed conflict. Fueled by the cocaine trade, this escalated dramatically in the 1980s. Since 2010 the violence has decreased, with some paramilitary groups demobilising as part of a controversial peace process and the guerrillas losing control of much of the territory they once dominated. Meanwhile Colombia's homicide rate almost halved between 2002 and 2006. As of 2011 Colombia remains the world's largest producer of cocaine, although production has been falling
