Where is the largest natural harbour in the world?

The Lower Harbour has many towns around its shores. Passage West, Monkstown, Ringaskiddy and the smaller village of Raffeen are found on the western shore. On the southwestern shore is Crosshaven. Great Island, which forms the northern shore of the lower harbour, houses the town of Cobh. The eastern shore is less densely populated, but has two villages Whitegate and Aghada.