​GERRHA (Arab. al-Jar ʽa), an ancient city of Arabia, on the west side of the Persian Gulf, described by Strabo (Bk. xvi.) as inhabited by Chaldean exiles from Babylon, who built their houses of salt and repaired them by the application of salt water. Pliny (Hist. Nat. vi. 32) says it was 5 m. in circumference with towers built of square blocks of salt. Various identifications of the site have been attempted, J. P. B. D’Anville choosing El Katif, C. Niebuhr preferring Kuwet and C. Forster suggesting the ruins at the head of the bay behind the islands of Bahrein.