The collection of articles in this issue broadens the perspective of sustainability in tourism in terms of both places and seasons. The focus is not only mountain areas, but also natural spaces such as parks and marginal rural areas. The two articles on over-tourism at Cinque Terre in Italy and in Corsica open another perspective: that of mountain and sea co-existing in the same space, with their unique dialectic relationship: walking in the mountain or bathing in the sea? Sipping an aperitif on the beach or visiting a small local trattoria in the hills? If mountain and sea are both present in the same place, sustainability is to be considered for both seasons, Winter and Summer.