Luzon, Philippines Luzon Island is largest among the Philippines' 7,107 islands, with an area of 104,687 sq km (40,420 sq mi). The island has two large lakes, Laguna de Bay and Taal. The Cagayan River, the longest river of the Philippines, flows generally north for about 354 km (220 mi). Agriculture is the chief industry on Luzon ... www.luzon.com