Arutanga is Aitutaki's main village and administrative hub — a small settlement on the western side of the main island where the government offices, a handful of shops, the post office, and the harbour are concentrated. It's not a destination in itself so much as the functional centre of the island: where the weekly cargo ferry ties up, where you go to buy groceries or petrol, and where the boat tours depart each morning.
The harbour area has a certain low-key charm in the early morning, when tour operators are loading gear and fishermen are sorting the night's catch. The CICC church near the waterfront is the village's most notable building and worth a visit, particularly on a Sunday. A short walk around Arutanga gives a clear picture of how a small Pacific island actually functions day to day, which is itself worthwhile context for the pristine lagoon and motu beaches you came here to see.