This work seeks to make a phenomenology of the human behaviour called "adventure" as well as of its own temporality. We try to characterise the most original or initial experience of adventure and its sedimentation in an attitude and vital form, potentially trivializable. In this sense, we will start from Simmel's (1910) essay on adventure, before turning to Jankelevitch's (1963) analysis, which includes this phenomenon in its relation to boredom and seriousness. Finally, we let these results be considered under the phenomenological and existential analysis in the Heideggerian sense, in order to define the art of world-opening that adventure represents, not only in its most proper sense, but also in the decadent ones, of repetitive type by pursuing sedimented expectations. The research moves in the horizon of the individual and his singular existence, as well as in the cultural one, seeking to recognize epochs of particular value due to adventure as an eminent life form.