This serene 315-sq-km national park covers 60km of Andaman coastline (Thailand's longest protected shore) and over 20 islands, including much-loved Ko Phayam. It's 85% open sea. Much of the coast is fringed by mangroves and laced with tidal channels, home to fish, deer, macaques, civets, giant squirrels and over 100 bird species, including white-bellied sea eagles.
The most accessible beach is gorgeous, casuarina-backed 3km Hat Bang Ben, home to the park headquarters and accommodation. To the south, peninsulas jut out into the ocean concealing isolated coves accessible only by long-tail. All these beaches are allegedly safe for swimming year-round. From Hat Bang Ben, spot Ko Kam Yai, Ko Kam Noi, Mu Ko Yipun, Ko Khang Khao and, to the north, Ko Phayam. If there's a prettier sunset picnic spot in the northern Andaman, we missed it.
Hat Praphat, 56km south of Hat Bang Ben, is a turtle nesting ground.