Sochi, city, southwestern European Russia, lying at the foot of the Caucasus Mountains, on the coast of the Black Sea. Sochi is an important health resort of Russia, with mineral springs and many sanatoriums. The region has a subtropical climate, and citrus fruit, tea, and tobacco are grown here. Sochi was founded in 1896 around the fortress Navaginskoye. The spa developed after 1910 and grew considerably in the 1930s and 1950s. Population (1999 estimate) 334,400.