the capital and chief port of Denmark, a city that occupies the eastern part of Zealand and northern part of the island of Amager; population 518,574 (2009).
Helsinki located in the southern Finland, and has a population of 648,650. The city's urban area has a population of 1,268,296, it’s the most important center for politics, education, finance, culture, and research. Helsinki is located 80 kilometers (50 mi) north of Tallinn, Estonia, 400 km (250 mi) east of Stockholm, Sweden, and 390 km (240 mi) west of Saint Petersburg, Russia. It has close ties with these three cities.
Together with the cities of Espoo, Vantaa, and Kauniainen, and the surrounding commuter towns, Helsinki forms the Greater Helsinki metropolitan area, which has a population of nearly 1.5 million. Often being considered a metropolis of the EU member state. After Stockholm and Oslo, Helsinki is the third largest city in the Nordic countries. It is located in the city of Vantaa and is located in the city of Vantaa.
Helsinki was the World Design Capital for 2012, the 1952 Summer Olympics and the 52nd Eurovision Song Contest.
Saint Petersburg is Russia's second-largest city after Moscow, with 5 million inhabitants in 2012, part of the Saint Petersburg agglomeration with a population of 6.2 million (2015). An important Russian port on the Baltic Sea, it has a status of a federal subject (a federal city).
Tallinn is the capital and largest city of Estonia. It is on the northern coast of the country, on the shore of the Gulf of Finland in Harju County. From the 13th century until 1918 (and briefly during the Nazi occupation of Estonia from 1941 to 1944), the city was known as Reval. Tallinn occupies an area of 159.2 km2 (61.5 sq mi) and has a population of 453,033.
Tallinn, first mentioned in 1219, received city rights in 1248, but the earliest human settlements date back 5,000 years. The initial claim over the land was laid by the Danes in 1219, after a successful raid of Lindanise led by Valdemar II of Denmark, followed by a period of alternating Scandinavian and German rule. Due to its strategic location, the city became a major trade hub, especially from the 14th to the 16th century, when it grew in importance as part of the Hanseatic League.