How is it that Lutherstrasse in the city center has nothing to do with the Reformer Martin Luther? Which house has a round hole above its entrance - and why? And what about the hooks that are attached to the walls of various buildings in the streets? The answers to these and 47 other questions have been explored by the authors Eva-Maria Bast, Kirsten Schlüter, and Heike Thissen, supported by the Ostthüringer Zeitung and numerous knowledgeable locals from Jena. They found that the City of Light, Jena, has an incredible amount to offer - including many mysteries! Of course, one cannot overlook Carl Zeiss, Ernst Abbe, and Otto Schott, who revolutionized microscope construction here. Even without Schiller and Goethe, who spent many years of their lives in Jena, such a book would not be complete.