The House of Tuzu

Tuzu is the tribe’s name for the island’s great central volcano. The ancients built a magnificent building in Tuzu’s name, containing mystical secrets for those who dare to approach.

The House of Tuzu is a community lot near the western shore of Felicity Island, one of the neighborhoods shipped with The Sims Castaway Stories. Like all community lots, it can be visited by using the travel map. Inside the temple there is quite a lot of treasure (though only viewable). But its main treasure is the Chalice of Youth, which can turn an elder Sim into an adult.

In the Shipwrecked and Single story, it is revealed that Winford Rhinehart knew about this place and was after the eternal youth it grants. Once the temple is opened, Rhinehart will run inside and drink from the chalice to turn into an adult. The protagonist can now choose Rhinehart's fate - banish him by making him dissappear forever or reward him by turning him into a toddler.