Gardaia, Or Gliardeia, a town of Algeria, in the province of Algiers, situated in the oasis of the Beni Mzab, on the Wady Mzab, in the Sahara, about lat. 32° 30' N"., Ion. 4° E.; pop. about 60,000. It is well fortified, having a wall with battlements and nine large towers, each of which is capable of holding from 300 to 400 men. Ten gates give entrance to the town, which contains a mosque of vast size and five smaller ones, besides a Jewish synagogue. The chief administration rests with the French bureaux arabes; the details of it are left to the native chiefs, who are generally little more than the mouthpiece of the high priest, whose advice has all the force of law. A flourishing trade is carried on with Tunis, Algiers, Bou Sada, etc, in corn, butter, groceries, oil, pottery, and negro slaves. The suburbs of the town contain extensive vineyards and orchards. Rain is almost unknown, but there are numerous wells, some of which are 900 ft. deep. On a neighboring eminence are the remains of a large tower supposed to have been built by the Romans. The oasis in which Gardaia is situated submitted to French rule in 1853.