Sulawesi is a large, odd-shaped island in the middle of the northern area of Indonesia. The principal city is Manado (MDC).
There are diving destinations all around the northern tip of Sulawesi, but the best and most famous is Lembeh Strait, situated between the "mainland" of Sulawesi and the island of Lembeh on the northeastern tip of Sulawesi.
We've been to Lembeh a number of times, staying at Lembeh Resort on the island of Lembeh.
North of Lembeh Strait is the small island of Gangga and Gangga Resort. We've stayed at this lovely place a number of times. There are plenty of critters and some nice reef dives as well.