MIMAROPA is an administrative region in the Philippines, designated as Region IV-B. It is one of two regions in the country having no land border with another region, the other being Eastern Visayas. The name is an acronym combination of its constituent provinces, which are: Mindoro (divided into Occidental Mindoro and Oriental Mindoro), Marinduque, Romblon and Palawan. The region is also formally known as the Southern Tagalog Islands.