Australia is the sixth largest country in the world - more or less the same size as mainland USA. This vast land however also has the lowest population density in the world, with only two people per square kilometre. Australia is politically divided into six states and two territories, each one offering a different experience for the traveller. There is the drama of the remote 'Outback', the colourful spectacle of the Great Barrier Reef and its coral islands, the excitement of the cosmopolitan cities, the sun and surf at some of the best beaches in the world, and the tropical rainforests of Western Australia. The list is endless in this diverse land of adventure, which boasts 2,000 national parks and 14 World Heritage-listed areas, along with more than 7,000 beaches. Australia is a land of character too, with its melting pot of cultures. For more than 50,000 years the Aboriginal people lived and thrived in the continent's unique environment. It is believed the Aboriginals are the world's oldest civilisation, and in recent years there has been a resurgence of interest in keeping the Aboriginal culture alive and flourishing. The vast continent at the bottom of the world was the last landmass to be discovered by European explorers. Captain James Cook arrived in Botany Bay in 1770 and sparked off generations of emigration to Australia, which for some time served as a penal colony. It was not until 1860 that two explorers - Robert Burke and William Wills - became the first Europeans to cross Australia from south to north. The country remains a magnet for modern explorers and adventurers and has a great deal to offer tourists and holidaymakers.