Why is this place built?

There's a legend which says that once,there were a Chinese sailor and a Malay fisherman who have been shipwrecked.Then came a very huge tortoise where it can carry both the Chinese sailor and the Malay fisherman on its shell.Therefore,in order to save them,the tortoise had to turn into an island and both men were safe.To remember the noble sacrifice of the tortoise, give thanks and to pay respects, a temple and some shrines were built on the island.Before the island was reclaim and became bigger plot of land of 85000 square metres in 1975,the island was used as burial ground for immigrants who had passed away while under quarantine at the nearby Saint John’s Island.

                                                                 (own pictures)
  http://www.guidegecko.com/singapore/kusu-island-travel-guide/p,608168062