Why are there high-rise buildings in Frankfurt?

Frankfurt is the leading high-rise city in Germany and one of just a few high-rise cities in Europe. No other city in Germany can boast such a skyline of skyscrapers, with more than 450 high-rise buildings (according to Phorio). 19 of Germany's 20 tallest skyscrapers are located in Frankfurt, and more than 50 new high-rise