 As such, it includes the Luzon mainland, the Batanes and Babuyan groups of islands to the north, Polillo Islands to the east, and the outlying islands of Catanduanes, Marinduque and Mindoro, among others, to the south.The islands of Masbate, Palawan and Romblon are also included, although these three are sometimes grouped with the Visayas.The name "Luzon" is thought to derive from the Tagalog word "lusong", a large wooden mortar used in dehusking rice.