Frankfurt is the financial capital of Europe, and the centre of the city is dominated by high-rise office blocks, dubbed ‘Mainhatten’ by the locals (because it’s on the river Main – ho, ho).
Surrounding the central area, the architecture is much more in keeping with a medieval city: early buildings interspersed with newer stuff. Many of the ‘old’ buildings are quite recent, however. Something like 85% of the city was destroyed during the Second World War, including many historic buildings. Much of what was destroyed has been rebuilt (for example, the Römer square) and looks as though the destruction never happened.
As a consequence of this rebuilding, Frankfurt presents a dual view: as you wander around the ‘older’ areas, you see early buildings against a backdrop of modern skyscrapers; a metaphor for the dual nature of the city, perhaps.