Join 科学与技术 upcoming events being held in Cortes. Cortes is a third class municipality located in the province of Surigao del Sur in the Philippines, known for its stunning natural attractions such as the Tinuy-an Falls, the widest waterfalls in the country, and the Britania Group of Islands, a collection of islets with turquoise waters and white sand beaches, making it an ideal destination for nature lovers and adventure seekers.