I am trying to model the Alexanderplatz in Berlin with the Fernsehturm and some other existing models from the Google Database. So I imported the area as a Geolocation. Then I imported the models and I realized, that the terrain of the geolocation is not flat, as it should be. I live there, so I know for a fact, that the Alexanderplatz is flat. It looks like there are bumps, where some high buildings where build and maybe some satelite scan got some data with high elevation from the rooftop of these buildings.
Now the question: Is there an easy way to select a point in the terrain as reference and make the rest of the terrain just flat?