Named after Malaysia's former prime minister, this largely marine-based national park is made up of a small grouping of islands within view of the city of Kota Kinabalu in Sabah. Comprised of Pulau Gaya, Pulau Manukan, Pulau Mamutik, Pulau Sapi, and Pulau Sulug, you'll find that these islands are a stellar opportunity to do the things you'd like to be doing in this part of the world: great diving and snorkeling, as some pristine beaches.
Pulau Gaya is the main island, where you'll find the park office, two resorts, plenty of rainforest trails, and the stellar Police Bay; while Pulau Manukan has a number of restaurants, a resort, and other tourist-centric services. The other islands are less-frequented and have little to no infrastructure, although campsites are available.
Due to great water clarity and the abundance of tropical fish (coral is limited due to dynamite fishing in the area), make sure you are prepared to get in the water, whether you take a ride with a dive center out to the high number of quality locations or you maverick it and throw a snorkel on at one of the many beaches. The bad news is that you'll be joining a lot of tourists in doing so, while you'll be privy to the obvious destruction of the reefs, which are near non-existent unless you're willing to swim far out from shore in less-tenanted islands like Sapi.
Be sure to pay the $14 USD or so for a diving permit and have a few rm on hand for conservation fees. For your convenience, we've included links to a few of the dive centers based out of Kota Kinabalu.