I visited this WHS in January 2020. I travelled around this WHS by rental car over 2 days using Guía de Isora as my base for 4 nights. This was quite convenient to explore different areas of the Teide NP while at the same time being close to Los Cristianos ferry terminal and South Tenerife Airport.

I had very high expectations for this WHS and I must say I definitely wasn't disappointed. It is a very well kept national park with free access, free parking, free visitor centres and a free botanical garden! The only time I had to pay was for the return Teleferico to the very top (27 eur) which is not at all necessary to still enjoy the OUV of this WHS.

During my visit I was blessed with beautiful sunny weather with temperatures varying from 1-23 degrees Celsius (depending on the altitude). Make sure to check the Teide weather report as it is quite possible to have completely different weather around Teide compared to the rest of Tenerife (most of the time you're likely to be above any cloud cover on Tenerife when visiting Teide NP). Moreover, at night and very early in the morning, it can snow quite a lot, so much so that the main roads can be closed at any given time should the authorities deem this necessary.

Over the course of 2 days, I stopped at practically all the several viewpoints or miradores along the TF-21 and the TF-38 main roads going through and around the Teide NP. At the beginning of both main road, on either direction, there are UNESCO WHS markers (no inscription plaque yet though). Each mirador has a number of different information boards bearing the UNESCO symbol.

The TF-38 main road is by far the busiest in terms of traffic but at no time of the day did I feel the place was overcrowded. The only place where later on in the day, parking and bus loads of tourist groups may be an issue, is at the Roques de Garcia Mirador and La Ruleta parking. Here there's a visitor centre under restoration or under construction and an expensive parador for those who want to actually sleep at the WHS proper. If you visit early in the morning, parking will be quite easy, however even if you visit later on in the day, there are a number of minor miradores or parking points on the side of the road just before the Roques de Garcia mirador. In fact, if you like hiking, I would recommend parking your car at the Mirador Llano de Ucanca (or even Mirador Boca Tauce if you're in for a long return hike) and hiking to Roque Chincado and Roques de Garcia.

At Mirador Boca Tauce, you'll be able to see 2 different types of lava flows from Pico Viejo: AA lava which is quite sharp and jagged and Pahoehoe lava which is much smoother. The Llano de Ucanca is now a sedimentary plain of what was possibly a temporary lake. The variety of landscapes here, together with the breathtaking view of the Teide volcano, make this a highlight of the national park which shouldn't be missed. Just before getting to the colourful hydrothermal alterations of Los Azulejos, you'll be able to gaze at the famous Roques de Garcia (already at an elevation of around 2070m). Most people reaching the Mirador Roques de Garcia will immediately head uphill thinking they'll be able to get a decent shot above Roque Chincado. However, the hike up has been chained off half-way as a safety precaution I suppose, so the best photos in my opinion can be taken just a few steps after the first big rock formation or from the Sendero 3 and 23 hiking trails. With a bit of luck and patience, you'll definitely be able to spot a lot of birds here such as the Canary Island Kestrel, Betherlot's pipit or Southern Grey Shrike.  

These incredible rock formations are actually called phonolytic and bifurcated dykes, that is channels from where the magma that fed the different eruptions which took place over time flowed up from. These rocks, which once lay very deep underground, were exposed when the area of Las Canadas was formed. From then onwards, these rocks have been worn away by erosion. The most famous rock is probably Roque Chincado. Its base is disintegrating more quickly than the upper part and eventually it will collapse under its own weight (perhaps this is why in a way it reminded me of the Azure Window which once stood in Dwejra, Gozo).

After quite a longish but satisfying hike, upon returning to the Mirador Llano de Ucanca, I crossed the road and hiked a bit upwards to view another peculiar rock formation known as Zapatilla de la Reina, which can easily be overlooked since you have to give your back to the splendid view of the Teide volcano to notice it.

One of the best miradores and hiking trails on the TF-38 main road, is definitely Mirador Samara. The volcanic cone of the Samara volcano has an interesting crater formed by a single eruption of pyroclasts, i.e. volcanic debris ejected into the air during an eruption. This mountain forms part of the most recent area of volcanic activity in Tenerife. Volcanic bombs can also be observed and on the summit there are nuanced mixtures of colours caused by oxidation. The hiking trail from this mirador allows you to walk among different volcanoes, namely the volcanic cone of the Samara volcano, and the Teide and Pico Viejo volcanoes, in a lovely Canarian pine forest landscape which is slowly taking over the black landscape of Narices del Teide and Los Regatones Negros.

At El Portillo, there's a small visitor centre showing a very interesting video on the Teide national park, and a botanical garden which is always open. It's a great place to spot the beautiful Tenerife blue chaffinch or Pinzon Azul, other finches and woodpeckers. Make sure you follow the Ruta Pinar de la Cumbre loop while walking around the botanical garden.

Close to the Pico del Teide, I was surprised and really happy to spot a flowering Tajinaste Rojo, so remarkable for its spectacular profusion of red flowers usually in Spring. This plant became very rare some 30 years ago when it was commonly eaten by livestock. However, since the banning of livestock grazing in the national park, the species has since recovered. The Tajinaste Rojo shoots can grow as high as 2 metres and around the park I could see several shoot 'skeletons'. Much of Teide's flora adapted to the harsh environment by reducing the size of the leaves, reducing the surface area to maintain constant temperature and humidity within its interior, generating a wax layer over the leaves to reduce water loss, seeking shelter in fissures and small ledges, growing for long periods underground, etc.

All in all, I really enjoyed this great WHS in Tenerife. Judging by how the rest of Tenerife developed and is developing, it certainly is a good thing that the Teide NP has been protected from early on. From all the volcano WHS I visited so far, this must be one of the best, and as a national park it really is world class in terms of size and quality (although I'm really looking forward to visit Yellowstone in the future to be able to compare).