Sea Fan City is a boat-access wall just off the Nunukan Islands, best treated as a controlled macro dive rather than a big open-water cruise. The site earns its name from the dense sea fan and gorgonian growth that gives the wall its character, and it is especially rewarding for buoyancy-controlled divers who like small-critter hunting, camera work, and a classic tropical wall profile with enough structure to keep each pass interesting. Local resort boats normally handle the run, which keeps the day simple once the weather window is right.