Before the Ice Age, the island formed part of the Crocker Range mass of sandstone and sedimentary rock on the mainland. However, about one million years ago, the melting ice brought about changes in the sea level and parts of the mainland were cut off by the sea to form the islands of Gaya Island, Sapi, Manukan, Mamutik and Sulug. Evidence of this can be seen from the exposed sandstone of the coastline forming the cliffs, caves, honeycombs and deep crevices. Jesselton Point Ferry Terminal in downtown Kota Kinabalu is the ferry terminal for those heading to the islands in
Tunku Abdul Rahman Marine Park (Gaya Island, Sapi Island, Manukan Island, Mamutik Island and Sulug Island). This ferry terminal is also the departure point for patrons staying at either Manukan Island Resort or Gayana Resort. In 1974, the major part of
Gaya and Sapi islands was gazetted as Tunku Abdul Rahman National Park, covering an area of . In 1979, the park was increased to with the inclusion of the three nearby islands of Manukan, Mamutik and Sulug islands. == Transportation ==