Sipadan Island (locally known as Pulau Sipadan) is known as one of the best diving site in world. This island is protected by government of Malaysia, so only few dives were allow per/day. Since the island was protected, only diving activity is allow here - the rest not because in order to preserve the nature of the island.
The underwater life here just like a heaven! - so many unique species found here. The famous site here is Barracuda Point, where you can find so many barracuda species swimming together. There are nine dive spots here and only 120 dives per/day are allow.
Getting here - you can reach from nearest island (Kapalai Island, Mabul Island or Mataking Island). Also you can reach to Sipadan from Semporna, the nearest town.
Guide and source:
Sipadan Island (Pulau Sipadan) from
Cuti-cuti Malaysia Travel Guide