Over the past 20 years, thousands of photos of old Frankfurt (Oder) and the historic Berlin government district have accumulated in my private archive. These documents serve as templates for my 3D reconstructions. In preparation for further VR tours, documentaries and book publications, I have also developed lectures on various streets, squares and buildings of these cities. These lectures are intended to deepen the content of some topics and to better illustrate them through the presentation of historical photos. In my lectures, the historical streets and buildings are always compared to the current state of construction. This makes the structural changes between the past and the present clearer to the audience.At the end of each lecture there is always the opportunity to exchange ideas and to look at the photo archive.