Ad-Dahna Desert passages which can be several kilometers long. Local Bedouin have always known these caves and some were used as water supplies. They were first systematically studied in the 1981, and later explored and reported by the Saudi Geological Survey. Ad-Dahna Desert The ad-Dahna Desert is the central division of the Arabian Desert. It is a corridor of sandy terrain forming a bow-like shape that connects an-Nafud desert in the north to Rub' al-Khali desert in the south. Its length is more than 1,000 km siding Twaik Mountains from the east and does not exceed 80 km in width. It is
Simpson Desert largely intact as the desert is uninhabitable. Therefore, habitats are not threatened by agriculture, but are damaged by introduced species, particularly rabbits and feral camels. The only human activitiy in the desert proper has been the construction of the gas pipelines, while the country on its fringes has been used for cattle grazing and contains towns such as Innamincka. Mound springs and other waterholes are vulnerable to overuse and damage. Protected areas of the ecoregion include the Simpson Desert, Goneaway, Lochern, Bladensburg, Witjira and Kati Thanda-Lake Eyre National Parks as well as the Munga-Thirri—Simpson Desert Conservation Park, Innamincka Regional Reserve