Las Canadas and El Tiede

Imagine an underwater volcano so large, it has grown from the deep ocean into an island nearly 4,000 m high. It is subject to a catastrophic collapse, the whole of its highest massif, the Caadas Edifice, falling back into the sea, leaving a huge abyss surrounded by a crescent of cliffs hundreds of metres high. In a mere 170,000 years, a new volcano grows that dwarfs the rim - remnant of its predecessor, filling the great hole with its hot spewings. It in turn is supplanted by its unruly offspring, so energetic that it nearly overwhelms its worn-out parent, growing so that it stands more than 500m above it, the tallest mountain in a mountainous country. That island is Tenerife; that clogged-up abyss the Las Caadas caldera; that young mountain, El Tiede.

The present caldera is 16km long and five or so wide, a series of arid gravelly-flats almost overwhelmed by the vast lava flows of the millennia.

This natural and visual drama makes for thrilling walking it is in our Top 100. If you can, spend at least two, preferably three days in this area.

While most walkers come to Tenerife to experience Las Caadas, or to climb El Tiede, there are many superb walking areas, and we recommend that, having made the effort to come here, you allow time to explore more widely.

From the score of fantastic walks in and just outside Las Caadas described by Cicerone and Sunflower, these are perhaps the best:

• El Tiede and Pico Viejo 
•  Guajara, the high point (in all senses) of the caldera rim with a couple of hours on the Caadas floor thrown in, and in our view the best overall walk.
• Roques de Garcia: superb scenery and volcanic nerdery, albeit over-popular.
• The 18km trail along the Caadas floor from El Portillo to the Parador. (You get quite a taste of this on the Guajara walk.)
• The tough but marvellous 24km along the Caadas rim, from El Portillo to the Parador. (You get quite a taste of this on the Guajara walk.)

Central Uplands

• The walk from El Portillo down into the La Orotava Valley.
• The short walk in the lava-gravel area around Samara or a longer but superb-sounding trail from La Montaaeta to Los Silos (Sunflower 16) through bleak, cindery scenery.
• Various walks from Las Caadas down the mountainside to the upland towns such as Vilaflor in the south, or north-west toward Teno, with wonderful sea views and volcanic scenery see the Cicerone guide (eg. walk 34): walk 41 sounds particularly intriguing, from Chiuyero down rounded slopes of dark cinders, littered with struggling Canary pines, bleakly beautiful and dotted with intriguing little craters and other volcanic detritus.