There has always been a rooftop terrace cafeteria in the Galeria Kaufhof department store on the western edge of the Zeil in downtown Frankfurt, but it recently got a new chef and was renamed Leonhard's. On nice weather days there's no better place to eat outside because of the great views of the Hauptwache plaza, Dom (cathedral), and western end of the pedestrian zone. It can get very crowded especially on weekends and if there is a festival.
The fare is pizza, traditional German food, and a salad bar with a limited selection of baked goods as well. Traditional Hessian apple juice and (alcoholic) apple cider (Ebbelwoi) are also offered along with an assortment of beers (bottled only). There is also a cafe for espressos and other coffee-based drinks that also serves ice cream. read more