They sometimes refer to the Banaue Rice Terraces - agricultural terraces carved into the Banaue Mountains in Ifugao province by the ancestors of the Igorot people (indigenous inhabitants of the Cordillera mountain range in northern Luzon). They are believed to have been created largely by hand.
The terraces are estimated to be more than 2000 years old, but several researchers dispute this estimate, believing that they were created much later. It is known, however, that rice is an ancient ancestral crop of the Philippines, having been brought to the islands by Austronesian migrations since at least 1500 BC.
The terraces are about 1500 meters above sea level. They are fed by ancient irrigation systems from the rainforest growing above them. Locals still grow rice and vegetables on the terraces, although farming is not an attractive industry for the young. The terraces are gradually eroding, and are also being destroyed by giant earthworms of the genus Pheretima ("olang" in the Ifugao language), as well as rodents of the genus Chrotomis mindorensis and snails.