Lithuania is a flatland, drained by the Nemen River. In addition to the capital, other important cities are Kaunas, Klaipeda (Memel), and Siauliai. About 84% of the population is Lithuanian; there are Polish, Russian, and other minorities. The major religion is Roman Catholicism and there are Russian Orthodox and Lutheran minorities. The Lithuanians speak a Baltic language (see Balts), which is the official language; Russian and Polish are also widely spoken.