Tallinn (historically known by the German and Swedish name Reval, among other names) is the capital and largest city of Estonia. It lies on the northern coast of Estonia, along the Gulf of Finland. The city is an important industrial, political and cultural center, and seaport.

Tallinn is situated on the southern coast of the Gulf of Finland, in north central Estonia. The largest lake in Tallinn is Lake Ülemiste (covers 9.6 km²). It is the main source of the city's drinking water. Lake Harku is the second largest lake within the borders of Tallinn and its area is 1.6 km². Unlike many other large towns, the only significant river in Tallinn is located in Pirita (a city district counted as a suburb). The river valley is a protected area because of its natural beauty. A limestone cliff runs through the city. It is exposed, for instance, at Toompea and Lasnamäe. However, Toompea is not a part of the cliff, but a separate hill. The highest point of Tallinn, at 64 meters above the sea level, is situated in the district of Nõmme, in the south-west of the city. The length of the coastline is 46 kilometres. It comprises 3 bigger peninsulas: Kopli peninsula, Paljassaare peninsula and Kakumäe peninsula.