The moon landscape we met when we entered the large caldera in Teide National Park (Cañadas del Teide National Park), in the centre of the island, on route TF-21 via Vilaflor was unlike anything we had ever seen. It’s a rocky wasteland of craters, solidified lava flows, and debris – was so unreal and forboding, that it is almost frightening.

Whereas Tobi revels in barren, alpine surroundings I usually miss colour and signs of life at higher altitudes. The sight of a volcano cone rising unexpectedly from this reddish-brown petrified lava landscape, devoid of vegetation except sparsely strewn straw-coloured tussocks and imperishable green shrubs, however, was fascinating.

By the time we passed the lower cable car station (Teleférico del Teide) and arrived at the trailhead for Refugio de Altavista (a mountain hut about half-way up to the peak of Mount Teide) at Montaña Blanca Sendero, the parking lot across the road had filled up already.

In that case, you can head back 850m to Tabonal Negro parking and walk along the road to the start of the trail, a gently climbing 4WD track (don’t think about shortcutting by driving up the track and parking higher up – from what we heard the rangers rigorously enforce all the park rules and cars are not allowed on the track).

After 50 minutes (4km) leisurely walking up a modest slope, we arrived at the Teide Eggs (Los Huevos del Teide) which are very large round balls of lava strewn about on a level plain that look like, well eggs, or giant marbles. This hike is all about rock, which, as I said before, surprisingly didn’t bother me.

The caldera resembles conditions on Mars so closely that astrologist come here to do research, and as I believed this was the closest I will ever get to setting foot on Mars, I was determined to appreciate rocks of all shapes and sizes (and colours) on this hike.

After 1:15 hours the dirt track narrowed to a steeper hiking trail that still wasn’t particularly challenging but, after 2:10 hours when we reached Refugio de Altavista at 3270m elevation, we began to feel the effects of ‘thin’ air at high altitudes. A low dense cloud cover hung around all day and obscured views of the island’s shoreline and the ocean beyond. The volcano cone rose well above the clouds however and the trail snaking up the slope was well visible for lack of vegetation.

We arrived at the well-frequented tourist trail that connects the upper cable car station with Mirador La Fortaleza after 3 hours hiking. The estimated time for this climb is 4-5.5 hours, however this feels very generous as we didn’t rush. The rather large number of gondola tourists floundering about in flip-flops and wearing T-Shirts at temperatures in single figures was hilarious as they had obviously misjudged the temperature at an elevation of 3555m above sea level.

We were sweaty from the hike and it was chilly as soon as we rested even on a very sunny day and wearing softshell jackets. Nevertheless, I made the very same mistake as many of these tourists a few days later when we were heading northwest towards Garachio and traversed the caldera again.

With temperatures in the mid-twenties along the shoreline I wore flip-flops, shorts and a T-Shirt and thought that a quick stroll to some viewpoints in the caldera couldn’t be all that bad in this attire if I just walked fast enough. Tobi kindly captured the moment when it started snowing and I watched snowflakes descend onto my naked feet. I hope this forever remains the only photo of me wearing flip-flops in the snow.

In case you want to access the crater summit, 200m higher up in elevation than the upper cable car station, you need to apply for a special permit beforehand. On the gondola we whisked down the slope in barely ten minutes, which I appreciated as a hint of mockery of the arduous ascent.

From the lower cable car station at kilometre 43, it’s a 3 kilometres walk back to the trailhead along a rather well frequented road (by Tenerife standards), so take care.