Kesklinn Administrative district in the centre of Tallinn Tallinn, the largest city and capital of Estonia (population 440 000). (pop. 66,000). is one of the eight administrative districts in Tallinn Tallinn, the largest city and capital of Estonia (population 440 000). , also the city centre (population approx. 66,000). The majority of Tallinn Tallinn, the largest city and capital of Estonia (population 440 000). 's cultural and public places are here, including government buildings, museums, theatres and several parks.