The archaeological history of the Northern Territory begins over 40,000 years ago when Indigenous Australians settled the region. Makassan traders began trading with the indigenous people of the Northern Territory for trepang from at least the 18th century onwards. The coast of the territory was first seen by Europeans in the 17th century. The British were the first Europeans to attempt to settle the coastal regions. After three failed attempts to establish a settlement (1824–28, 1838–49, and 1864–66), success was achieved in 1869 with the establishment of a settlement at Port Darwin. Today the economy is based on tourism, especially Kakadu National Park in the Top End and the Uluṟu-Kata Tjuṯa National Park (Ayers Rock) in central Australia, and mining.