Photo: Wikimedia CommonsA Frankfurt institution since 1951, Jimmys Bar in the basement of the Hessischer Hof is a wood-panelled, low-lit classic where a pianist plays nightly and the barmen mix proper old-school cocktails. It draws an elegant, all-ages crowd and stays open very late. Dress smartly, order a dry martini or a whisky sour, and settle in for the live piano; it is one of the last great grand-hotel bars in the city.