You not only get heritage and bike trails but those underwater too! One of the best things to do in Singapore for divers is to explore the Sisters' Islands Marine Park which has specially marked shallow and deep trails beneath the waves. Be it giant clams, sponges, hard and soft corals, clownfish, sea anemones, schooling fish or sea stars, there is much to see on these trails; along the way, you will come to specific stations with information on the diverse marine biodiversity and the importance of conservation.