The Siwa Oasis (Siwi: Isiwan; Arabic: واحة سيوة Wāḥat Sīwah, IPA: [ˈwæːħet ˈsiːwæ]) is an oasis in Egypt, located between the Qattara Depression and the Egyptian Sand Sea in the Libyan Desert, nearly 50 km (30 mi) east of the Libyan border, and 560 km (348 mi) from Cairo.
About 80 km (50 mi) in length and 20 km (12 mi) wide, Siwa Oasis is one of Egypt's most isolated settlements, with 23,000 people, mostly Berber speakers who speak a distinct language of the Berber family known as Siwi. Its fame lies primarily in its ancient role as the home to an oracle of Amon, the ruins of which are a popular tourist attraction which gave the oasis its ancient name Ammonium. Historically, it is part of Ancient Libya. Its modern name Siwa, first attested in the 15th century (earlier Arab geographers termed it Santariyyah), is of uncertain origin. Basset links it to a Berber tribal name swh attested further west in the early Islamic period, while Ilahiane, following Chafik, links it to the Tashelhiyt Berber word asiwan, a type of prey bird, and hence to Amon-Ra, one of whose symbols was the falcon.