Tallinn is the capital and most populous city of Estonia. Situated on a bay in north Estonia, on the shore of the Gulf of Finland of the Baltic Sea, Tallinn has a population of about 457,000 and administratively lies in the Harju maakond (county). Tallinn is the main governmental, financial, industrial, and cultural centre of Estonia. It is located 187 km (116 mi) northwest of the country's second largest city, Tartu; however, only 80 km (50 mi) south of Helsinki, Finland, also 320 km (200 mi) west of Saint Petersburg, Russia, 300 km (190 mi) north of Riga, Latvia, and 380 km (240 mi) east of Stockholm, Sweden. From the 13th century until the first half of the 20th century, Tallinn was known in most of the world by variants of its other historical name Reval.