Hamburg is the second largest city in Germany in terms of population. It is the most populous city in the state of Hamburg and the fourth most populous agglomeration in Germany after the Ruhr, Rhine-Main and Frankfurt am Main. The city is also the second largest port city in Europe and the eighth richest city in Germany. Hamburg is a city-state. It is one of the richest cities in the country. It is the only German city to have retained the status of city-state. The city is divided into 7 districts: Altona, Eimsmünde, Bergedorf, Eppendorf, Harburg, Nord and Wandsbek. The port of Hamburg is the second largest and second most important in Europe after Rotterdam. Hamburg is a very touristy city and thousands of tourists pass through every year. Speaking of tourism, there are many things to visit in Hamburg: the port, the Elbe, the Alster, the old town which is called Speicherstadt, Reeperbahn which is the heart of the city's nightlife, the new synagogue, the botanical garden, as well as many museums.