Western Desert   The Western Desert covers about 700.000 square kilometers (about the size of Texas) and accounts for two thirds of Egypt's land area reaching from Mediterranean Sea south to the Sudanese border.   Limited agricultura production, the presence of some natural resources and permanent settlements are found all of which have fresh water proided by the Nile or by local groundwater.  The Siwah Oasis, close to the Libyan border and west of Qattara, is isolated from the rest of Egypt but has sustained life since ancient times. The Siwa's cliff-hung Temple of Amun was renowned for its oracles for more tham 1,000 years. Herodotus and Aexander the Great were among the many illustrious people who visited the temple in the pre-Christian era.