Luzon may also refer to one of the three primary island groups in the country. 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 CatanduanesMarinduque and Mindoro, among others, to the south.[4] The islands of MasbatePalawan and Romblon are also included, although these three are sometimes grouped with the Visayas.