Sydney is the capital city of the state of New South Wales and the most populous city in Australia. Located on Australia's east coast, the metropolis surrounds Sydney Harbour and extends about 80 km (50 mi) from the Pacific Ocean in the east to the Blue Mountains in the west. Residents of the city are colloquially known as "Sydneysiders". The city's nicknames include the "Emerald City" and the "Harbour City".