A network of ancient aqueducts provides water to three valleys in the Peruvian Nazca region, converting a desert area into fertile farmland where potatoes, cotton, vegetables and fruit trees are grown. The aqueducts were built over 1600 years ago by the inhabitants of the Nazca culture and are on UNESCO's tentative list to be declared a World Heritage Site. "We estimate that 29 aqueducts are still in operation and thanks to this hydraulic system, as you can see, the entire valley is green, so the importance of this system for agriculture is also important," says archaeologist Abdul Yalli. IMAGES AND SOUNDBITES