Today was literally a washout, as we went to a water park on Sentosa Island. But it's more than just theme parks, it's Singapore's playground. It's like a jungle island with fancy beach resorts, but full of entertainment from bungee jumping, to iFly, a casino, luge track. You could easily stay on the island and not see the rest of city.
Also, Sentosa is the southern most tip of the Asian continent.