It is believed that taro cultivation drove the start of terracing in the Cordilleras less than one thousand years. Taro was later replaced by rice around 1600 A.D., which is the predominant crop today. Although there is lack of solid evidence that paddy rice was cultivated in the Philippines earlier than about 700 years ago, the start of rice cultivation was a major development in Filipino cuisine. Using only basic tools, the Ifugao built the Banaue Rice Terraces using stone and mud walls to create flat surfaces on the steep mountain slopes, which allowed them to cultivate rice in the highlands. The plains of central and southwestern Luzon, Bicol peninsula, and eastern Panay were major producers of rice, exporting surplus elsewhere to the rest of the archipelago. Rice was a symbol of wealth, with many rice-based delicacies used as offerings in important ceremonies. Like much of Asia, rice is a staple of Filipino cuisine. Rice-based dishes are common among all regions, with influences from various countries, e.g., arroz caldo is similar to Chinese congee.