Berlin is the capital city and one of sixteen states of Germany. With a population of 3.4 million within its city limits, Berlin is the country's largest city. It is the second most populous city and the ninth most populous urban area in the European Union. Located in northeastern Germany, it is the centre of the Berlin-Brandenburg metropolitan area, comprising 5 million people from over 190 nations. Berlin has one of the most diverse and vibrant nightlife scenes in Europe. After the fall of the Berlin Wall in 1989, many buildings in Mitte, the former city center of East Berlin, were renovated. Many had not been rebuilt since the Second World War. Illegally occupied by young people, they became a fertile ground for all sorts of underground and counter- culture gatherings. It is also home to many nightclubs, including Kunst Haus Tacheles, techno clubs Tresor, WMF, Ufo, E-Werk, the infamous Kitkatclub and Berghain. The Linientreu, near the Kaiser Wilhelm Memorial Church, has been well known since the 1990s for techno music. The LaBelle discotheque in Friedenau became famous as the location of the 1986 Berlin discotheque bombing.