Following up on several of our researches about the body in space, this article more precisely takes the side of analyzing the mutations of body/place relations by considering nature (wilderness in a French sense) as intermediation. It is about grasping this relationship at the limits of the possible, that is to say involving excesses at the level of the body as well as at the level of nature. Our choice fell on sports described as extreme and on one of the archetypal figures of these activities: Marco Siffredi, freerider of the most dizzying slopes in the world at the end of the 1990s and who disappeared while snowboarding on Everest in September 2002.