New South Wales is the most populated states in Australia (about 7.2 million people). Its capital is probably one of the best known cities of Australia, Sydney, although it isn't the capital of the country (which is Canberra in the Autralian Capital Territory, or ACT).
The Northern Territory is one of two territories in Australia. Sparesly populated (about 230,000 people) it's the home to Uluru and Kakadu - both famous World Heritage areas.
