The island of Pulau Banggi, 40km north of Kudat and accessible by daily ferry, is the largest in Sabah (Malaysia). It's mostly flat but has lovely beaches, including one close to the jetty at the main settlement Karakit, and is worth a visit just for the boat ride and an amble on the beach. There are few tourist facilities; to dive the reefs here, for example, you'd need to make arrangements with a tour company in KK.
