This chapter provides a brief introduction to the origin of the island of Tenerife as a result of volcanic eruptions arising from the depths of the Atlantic Ocean. We have also decided in this introduction to limit ourselves to making a few brief comments on the people, mostly scientists, of some importance, who in their respective visits to the island managed to climb to the summit of Teide in those difficult times of the eighteenth century, the century of enlightenment when the possibility of breaking a backward and retrograde culture to give way to the great beginning of free thought was opened to the world. Great figures of eighteenth-century European culture contributed decisively to promoting new scientific progress. The travellers of the time who were great naturalists knew the singularities of the island of Tenerife through the classical authors, the conquistadors and chroniclers from the fifteenth century onwards and it was they from the eighteenth century onwards, imbued with the spirit of the moment, who carried out more precise studies and descriptions of the nature of the island and its biodiversity in their ascents to the peculiar Teide volcano.