In Greek mythology, Tiasa (Ancient Greek: Τίασα) was a nymph of a riverCf. also Hesychius of Alexandria s. v. Τίασσα: "Tiassa: a spring in Lacedaemon; according to some a river". A "fountain of Tiassus" is also mentioned in Athenaeus, Deipnosophistae 4.139B near Amyclae, Sparta. She was a Laconian princess as the daughter of King Eurotas and Cleta, and thus sister of Sparta.
By the river Tiasa was situated a temple of Cleta and Phaenna, the two Charites recognized in Sparta, which was purported to have been founded by Lacedaemon.Pausanias, 3.18.6
Notes
References Athenaeus of Naucratis, The Deipnosophists or Banquet of the Learned. London. Henry G. Bohn, York Street, Covent Garden. 1854. Online version at the Perseus Digital Library. Athenaeus of Naucratis, Deipnosophistae. Kaibel. In Aedibus B.G. Teubneri. Lipsiae. 1887. Greek text available at the Perseus Digital Library. Pausanias, Description of Greece with an English Translation by W.H.S. Jones, Litt.D., and H.A. Ormerod, M.A., in 4 Volumes. Cambridge, MA, Harvard University Press; London, William Heinemann Ltd. 1918. . Online version at the Perseus Digital Library