El Portillo is a gap in a wall, which is what the name means in Spanish, and the wall is the rim of an enormous collapsed volcano. The road climbs from La Orotava through a belt of Canary pine forest to this pass at around two thousand metres, and then the trees thin out, the ground turns to pumice and ash, and the whole of Las Cañadas del Teide opens up in front of you: a vast caldera with the cone of Teide rising from it. It is one of the more abrupt changes of scene on any road in Europe.
Teide, at 3,715 metres, is the highest mountain in Spain and the third-highest volcanic structure on Earth when measured from the sea floor. The Guanches, the original inhabitants of Tenerife, believed it was the home of Guayota, a demon who pulled the sun from the sky, and they considered it sacred. The national park here, a UNESCO World Heritage Site, covers a landscape of lava flows, pumice fields and strange rock formations, with a flora of its own, including the Teide viper's bugloss, a tall spike of red flowers that blooms in late spring. The visitor centre at El Portillo has exhibits and a small botanic garden.
The ride from the north is the best way in. The road from La Orotava climbs steadily through pine forest in broad bends, then reaches a long straight over the pass, with the volcano ahead. It continues across the caldera floor through a landscape that looks like another planet, with colours ranging from black and red to yellow and white. The surface is excellent, the road is wide, and the traffic is steady. Wind and cold at this altitude are real: temperatures can drop below freezing at night even in summer, and snow closes the road occasionally in winter. Cloud often lies below the pass, and the transition from the grey sea of cloud to the clear blue sky above is dramatic.
Fill the tank in La Orotava or Los Realejos before you start, because the next reliable stations are on the other side of the island. A café and small restaurant at the pass serves hot food, and a few picnic areas are scattered through the pine forest below.
Go early, since the afternoon cloud often rises and hides the cone.