The coast of Peru is one of the driest places on earth. With no rainfall during the year, only the snowmelt from the Andes provides a water source in distinct river valleys that cross the coastal desert. Near those valleys cultures have thrived for millennia. And because of the dryness their adobe ruins, buried artifacts and even bodies have survived remarkably intact. North of Lima we visited the 5000 year old site of Caral and saw artifacts and monuments from the Chavin culture (800BC), the Moche (500AD), the Sicán (1100AD), the Chimu (1300AD) and one of the few coastal Inca sites (1500AD) along the coast just south of Lima.