The coastline of the Great Australian Bight is characterised by cliff faces (up to high), surfing beaches and rock platforms, ideal for whale-watching. This is a popular activity during the southern hemisphere winter, when increasing numbers of southern right whales migrate to the region from their summer feeding grounds in the Antarctic. The whales come to the Bight region, especially to the Head of Bight, to calve and breed, and do not feed until they return to the Antarctic. Their numbers were severely depleted by whaling, particularly during the 19th Century, but have since recovered to some extent.