A united Germany's capital since 1999, Berlin has evolved into a cosmopolitan city to rival both London and Paris. Following World War II and the fall of the Nazi regime, Berlin became a divided city, partitioned into British, French and American zones in the west, and a Soviet zone to the east. The western zones gradually merged into West Berlin while the eastern zone continued to fall under Soviet rule. Following the collapse of the Berlin wall in 1989, the city's two haves were re-united and eventually became Germany's capital, yet again. *** Local Caption *** As part of Albert Speer's plan for the reconstruction of Berlin during the Nazi era, Prof. Ernst Sagebiel was ordered to replace the old terminal with a new terminal building in 1934. The airport halls and the neighbouring buildings, intended to become the gateway to Europe, are still known as the largest built entities worldwide, and have been described by British architect Sir Norman Foster as "the mother of all airports".