Even before his arrival on the islands, the Prussian naturalist's Canarian adventure was far from dull. At the end of the 18th century, the unstable nature of European politics saw clashes, for the umpteenth time, between English and Spanish interests. This led to an English flotilla being stationed in the Canarian seas with the intention of blocking the maritime connections between the islands and with the rest of the world. Thanks to the skilful manoeuvrings of the ship's captain, Von Humboldt finally reached Santa Cruz de Tenerife on 19th June 1799 aboard the Spanish sailing ship Pizarro. "Since Greek and Roman times, Tenerife has been renowned for its landscape. These days, nearly all travellers from around the world include it on their route towards the Cape of Good Hope", the naturalist noted in his diaries.

Humboldt was a important figure in natural sciences during the late 18th and early 19th century. A tireless traveller, he roamed the world in search of new plant and animal species to add to his collection and advance his studies, consequently gaining a position of prominence in this new field of science. He took full advantage of his stay in the Canaries and it is said that just a few hours after disembarking in Tenerife, he was already rummaging around on the outskirts of the island's capital amassing samples for his botany collection. He fell in love with the island, despite his short stay there, and it gained a special place in his heart: "I am on the verge of tears as I leave. I wish I could come and live here", he wrote to his brother before setting sail from Santa Cruz.

However, one of highlights of his stay in Tenerife was undoubtedly the expedition he organised to the top of Teide, which he described as "the first active volcano that I have the pleasure of visiting". He explained: "A single path leads to the volcano. It is the same path followed by Father Feuillée, Borda, M. Labillardière, Barrow and many travellers who were only able to stay in Tenerife for a short time. The excursion to the peak is similar to those frequently organised in the Chamouni valley and to the summit of Etna, where it is necessary to follow the established routes; all one ever sees is that which has already been seen by other travellers". Despite retracing the steps already taken by others, Von Humboldt set off, full of enthusiasm. He was constantly surprised by everything that he saw around him and, while climbing to reach his destination, he set himself a task which had yet to be realised: "in none of these (old) accounts, have I seen a description of the nature, the shapes of the mountain, the growth of the plants, that is, all those things that characterise the island".  

With this in mind, he accomplished his task and was one of the first to notice the presence of an unusual violet "similar to the Viola decumbens, which is found on the slopes of the volcano up to a height of 1740 toesas, higher than the other herbaceous plants, as well as the grasses, that on the Alps and on the back of the mountain range are in direct contact with vegetation from the criptogamic family". The now famous Teide Violet, a species endemic to the summit, caught the attention of the Prussian naturalist, who also speaks of the Ice Cave, as well as the dramatic sunrise viewed from the volcano's crater, "I would describe the peak of the summit of Teide at the time when a horizontal layer of a radiant white cloud separates the cone of ashes from the lower plain, and soon afterwards, through the effect of an ascending current, from the edge of the crater the eye is drawn to the vineyards of La Orotava, the orange orchards and the dense clusters of banana tress on the coast [...] All that the senses struggle to capture, the most surprising of romantic landscapes which can become a source of pleasure for man; at such times our imagination is free to exercise its creative power".
Humboldt left Tenerife after six days and continued on his voyage to the South American coast. Even though he was enchanted by the beauty of the island, he would never return to the place where, according to his assistant Bonpland, he spent "the loveliest days of his life".