Motuarohia Island (Roberton Island) is a small island in the Bay of Islands of New Zealand, located about 4 kilometres (2.5 mi) northeast of Russell.The island stretches for 2 kilometres (1.2 mi) east-west, with the south coast offering two bays backed by sandy beaches. The north coast is dominated by steep cliffs in the west, rising to 78 metres (256 ft), and two shallow lagoons in the west. The twin lagoons nearly reach across the island to the bay on the south coast, almost bisecting the island.