and the I, II, XI and XII on the Buda side of the city. District I is a small area in central Buda, including the historic Buda Castle. District II is in Buda again, in the northwest, and District III stretches along in the northernmost part of Buda. To reach District IV, one must cross the Danube to find it in Pest (the eastern side), also at north. With District V, another circle begins, it is located in the absolute centre of Pest. Districts VI, VII, VIII and IX are the neighbouring areas to the east, going southwards, one after the other. District X is another, more external circle also in Pest, while one must jump to the Buda side again to find Districts XI and XII, going northwards. No more districts remaining in Buda in this circle, we must turn our steps to Pest again to find Districts XIII, XIV, XV, XVI, XVII, XVIII, XIX and XX (mostly external city parts), almost regularly in a semicircle, going southwards again. District XXI is the extension of the above route over a branch of the Danube, the northern tip of a long island south from Budapest. District XXII is still on the same route in southwest Buda, and finally District XXIII is again in southernmost Pest, irregular only because it was part of District XX until 1994. Demographics Budapest is the most populous city in Hungary and one of the largest cities in the European Union, with a growing number of inhabitants, estimated at 1,763,913 in 2019, whereby inward migration exceeds outward migration. These trends are also seen throughout the Budapest metropolitan area, which is home to 3.3 million people. This amounts to about 34% of Hungary's population. In 2014, the city had a population density of 3,314 people per square kilometre (8,580/sq mi), rendering it the most densely populated of all municipalities in Hungary. The population density of Elisabethtown-District VII is 30,989/km2 (80,260/sq mi), which is the highest population density figure in Hungary and one of the highest in the world, for comparison the density in Manhattan is 25,846/km2. Budapest is the fourth most "dynamically growing city" by population in Europe, and the Euromonitor predicts a population increase of almost 10% between 2005 and 2030. The European Observation Network for Territorial Development and Cohesion says Budapest's population will increase by 10% to 30% only due to migration by 2050. A