There are 6 islands in the Phi Phi group; Phi Phi Don, Phi Phi Ley, Bida Nok, Bida Nai, Koh Yung, and Koh Phai; total land area is 42 square kilometers. The islands were declared a National Park in 1983, and development is limited to Koh Phi Phi Don only. All other islands are uninhabited.