What are those pink pipelines winding their way around the city? An art installation? The course of the former Berlin Wall? Or are they gas pipes? None of the above. They are part of the city’s drainage system. Berlin was founded in a very swampy area, which means the groundwater level, especially in the city center, is quite close to the surface, flooding construction sites whenever the foundations of a new building are laid. The pink (or, in some cases, blue or yellow) pipelines pump it all away. If you follow them to one end you will come to either a building site or a waterway. The twists and turns are merely to prevent the pipes from bursting in freezing winter temperatures. Mystery solved!