Two days of colour-infused serenity, Kassel Garden Culture is about as refreshing as festivals get. This is one of the greenest cities in Germany and it is keen to show it off, and two days in May are accentuated by events in all of the parks and gardens of this marvellous town. Art, music, readings, food and more are on offer, as well as plenty of guided walks that will uncover the secrets of Kassel, all while getting plenty of much-needed air into those thankful lungs. One of our favourites.