To the west are the northernmost peaks of the Andes, which are divided into three sub-ranges. Beyond these extend the low plains, with many rivers. Most of the rainfall occurs between March and May and between October and November.
Temperatures vary with altitude.
Recent years in Colombia have been dominated by endemic violence, with threats to government control coming from both left wing guerrillas and drug-trafficking cartels. Colombia, Bolivia and Peru have joined with the USA in an attempt to eliminate the cocaine and heroin trade, but in Colombia the results have been mixed. The highly publicized death of Pablo Escobar, a notorious drug trafficker, merely resulted in the establishment of another cartel based in Cali. Ernesto Samper, a Liberal, who gained the presidency in 1994 with a narrow victory over his Conservative rival, was accused of funding his campaign with money from the drug barons. However, no doubt under strong US pressure, he has recently waged a powerful and moderately successful crackdown on the Cali syndicate.