A scatter of small islands in the strait south of Sentosa, reached by ferry or chartered bumboat from Marina South Pier, offering a version of Singapore that has barely changed in decades. None of them takes more than half a day to see properly, which makes them an easy add-on to a Sentosa trip or a half-day escape from the mainland on their own.
Kusu Island is the most visited, drawn by a Taoist temple and Malay shrine built around a turtle-rescue legend — quiet most of the year, packed with pilgrims during the ninth lunar month. Lazarus Island, linked by a causeway to St John's Island, has one of Singapore's best undeveloped beaches and no facilities at all, which is the point. Sisters' Islands, a little further out, is a proper marine park with the clearest snorkelling water near the city and an active coral restoration program. Pulau Hantu, reached only by charter boat, has a coral lagoon that is the best snorkelling spot accessible from the mainland.
Pulau Sekang, visible from the water between Sentosa and the Riau Islands, is not open to the public — the kampong that once stood there has largely disappeared, and what remains is of historical rather than practical interest.
Ferries to Kusu and St John's/Lazarus run on a fixed schedule from Marina South Pier. Sisters' Islands and Pulau Hantu have no scheduled service and require a chartered bumboat or a guided tour. None of the islands has shops or restaurants — bring water, sunscreen, and a packed lunch.