Photo: GetYourGuideCologne Zoo is one of the oldest and most respected zoos in Germany, home to elephants, big cats and a superb aquarium and rainforest hall, set in leafy grounds north of the centre. It is a great half-day out for families. Book a timed ticket, allow a few hours to see the elephant park and the aquarium, and reach it easily by the U-Bahn or the cable car.