Chuí, Rio Grande do Sul (Brazil) - "Extremo Sul Ultramarathon". The longest beach in the world - 226km of an immense beach, on a tremendous sand plain, in an inhospitable, climatically unstable place with enormous contrasts. 52 hours maximum time to travel the route between sand and sea, in a corridor that can sometimes seem infinite and psychologically exhausting. https://horizontes.pt/en/extremo-sul