Lava tubes of Tenerife, 2010
(based on an article in MCG News Number 364 November 2010, Ed Waters)
Back in June, Hayley and I gate crashed what has become a regular Wessex Cave Club holiday to Tenerife. Under the guidance of Andy Morse and Les Williams, they have got to know both the caves and local cavers on the island very well over a large number of visits over the last ten years or so. Knowing our interest in volcanic caves, Les had invited us to join them.
For those who are unaware, Tenerife boasts the longest lava tube caves outside of Hawaii. Unfortunately access to many of the best caves is severely restricted for conservation reasons. However, Andy and Les’s contacts ensured that we would be able to gain access to many of these sites. As with the MCG Spain expedition, caving without the correct paperwork can end you in serious trouble.
As well as the caves Tenerife has some spectacular volcanic scenery
These caves lay conveniently right next to the road between the airport and our accommodation. This allowed us a brief introduction to Tenerife's caves. Cuevas Samara consists of a number of linked caves, Les and Andy's knowledge came to the fore in showing us a couple of entrances that are deliberately obscured with boulders. An hour or so's fun was had clambering into each of the entrances and exploring the couple of hundred metres of cave passage, some of it quite large at 3m high and wide. In a couple of places the passage is well decorated with spiky sharp splash stalactites.
Cuevas de San Marcos and Cueva de Punto Blanco
The first real day of caving was to be down on the coast, in the sea cliffs above the town of San Marcos. The caves are located along a small footpath that follows the bottom of the cliff from the edge of town, with climbs up to each cave. We walked past the climb to Cuevas de San Marcos (aided with a strategically placed scaffold bar) and headed round to Cueva de Punto Blanco first.
The 3m climb was awkward enough for us to rig a ladder for the return. Apparently this had been 'rigged' with a dodgy wooden ladder in previous years.
Though only a short cave, of perhaps 250m in total length, it is well worth a visit. In particular it has some fine passage forms, and a superb lava cascade complete with eroded rafted block at the top of it. We also took time to crawl round and look out of the second entrance, about 15m up the cliff face.
Heading back round the cliff we then clambered up into the far more extensive Cuevas de San Marcos. The low entrance crawl soon opens out into a fine large passage, including some impressive lateral benches. The cave contains about 2.5km of passage with several oxbow loops, and a passage climbing to a second (gated) entrance. Perhaps the finest feature in the cave is a lava pool upon which a thin surface layer had solidified before it drained. The unsupported skin then dropped back into the pool, frozen in time.
Cueva de Hoya de San Felipe
The low entrance to this cave lies alongside the hard shoulder of the dual carriageway through Icod de los Vinos. The cave was discovered during construction of the road, and surveyors from the civil engineers mapped about 800m of passage. However, there is considerably more passage in this cave. We surveyed another 500m or so beyond a rather nasty squeeze, and there is more still to do.
The cave is fairly sporting for a lava tube, involving some interesting squeezes and climbs in addition to some fine large passages. Route finding presents more than a few challenges too, as high level crawls are used to bypass blockages between sections of a fine large trunk passage. In places the trunk passage displays a superb lava trench in its floor, akin to a keyhole passage shape in a limestone cave.
Cueva del Viento (Cueva del Sobrado - Cueva de los Breveritas Traverse)
The Cueva del Viento system is the longest lava tube cave outside of Hawaii, with over 17km of passage mapped to date. The system has evolved through the linking of a number of formally separate caves namely Cueva de los Breveritas, Cueva del Sobrado and Cueva de los Piquettes. It is a complex labyrinthine system descending steeply underneath the town of Icod de los Vinos. Indeed it manages a respectable 'depth' (vertical range) of 560m.
Due to the notoriety of the cave (it was for a time considered the longest lava tube in the world) the cave has suffered much damage from careless visitors. For this reason the Breveritas section is gated a few hundred metres from the entrance. As the Sobrado section has been developed as a show cave, this too is gated meaning that the vast majority of the system is only accessible with the correct permission – which is rarely given.
However, due to the contacts built up between the Wessex group and the local Benishares club (who also run the show cave) we were very privileged to be allowed to carry out the traverse between Cueva del Sobrado and Cueva de los Breveritas. The trip had to be made after the show cave had closed for the day, so we arranged to meet the Benishares group at 6pm. It was clear that this was a big event, with a large number of Benishares and other Canarian cavers joining in too. In total there were 26 in the party! Somehow sorting out the caving managed to take three hours, we didn't get underground until 9pm.
Alfredo (the local head honcho as far as caving is concerned) had told us to expect a 9 hour trip, and warned us of three desperate squeezes en-route. He explained that he was not sure whether he would still fit through the squeezes, as it was five years since he (in fact it turned out anyone) had been through the connection.
The trip starts easy enough, with a gentle walk upflow in the Sobrado show cave, quickly reaching a gate. Beyond the gate is initially easy walking to the furthest upflow reaches of Cueva del Sobrado, where a short traverse leads to a climb up into a low roof tube that is part of the upper series. This leads to a series of flat out crawls on sharp lava in an extremely complex maze of passages.
Soon the first squeeze was reached. This is a flat out passage, about two body lengths long and about 30cm high. In limestone this would be no real obstacle, but on the sharp floor and a roof festooned with razor sharp mini-stalactites it would have been a serious proposition if Alfredo had not brought a length of kitchen lino to lay on the floor. This is a top tip for lava squeezes!
Beyond the first squeeze is a series of boulder chambers which contain the actual link between Cueva del Sobrado and Cueva de los Breveritas. The link had been filled in some years before due to the danger of vandals entering Cueva del Sobrado from the (then) ungated Cueva de los Breveritas. Alfredo told us that no one had been through the connection in 5 years, and as part of the honour of being on the reopening party we could dig it open again!
This connection proved to be the second squeeze. Much bigger than the first it is however very loose and great care needs to be taken when passing through the choke. In addition further care is required passing a fine display of pure white secondary formations at the end of the squeeze.
Once out of the squeeze, the way on is to drop down into the main trunk passage of Cueva de las Breveritas. This is mostly easy walking, and after a lengthy stop for dinner we headed off thinking that we had cracked it.
Soon the passage contracts down to a nasty little crawl with a particularly painfully lumpy floor. The long snake of cavers came to a halt, and we stayed like this for maybe 30 minutes without moving. Eventually word made its way back along the queue that we had reached the final squeeze. Alfredo was through (just), but one person had failed to get through after much heroics and stripping of clothes (and flesh). Several people questioned whether I would fit through, so I was forced towards the front to test my girth.
This squeeze is particularly nasty, a vertical slot in the roof of the flat out crawl. The walls are razor sharp, but again Alfredo had come to the rescue with two sheets of lino to take the edge (literally) off the squeeze. From above Les encouraged me, 'Bloody tight this, I counted every rib through, not sure you'll make it'.
With my confidence thus reinforced I attempted the squeeze with more than a little trepidation, but found it relatively easy – much to Les's disgust!
With all but one through, someone now had to go back the way we had come as the unfortunate Brit did not know the way back. It then transpired that in fact only Alfredo knew the way well. He was obviously not keen as apparently he had really struggled to get through the squeeze coming up. However, he is made of stern stuff, and stripping down to bare skin on lava ignored the pain and the flashes of numerous cameras.
The squeeze emerges in the floor of a large passage that leads down to the Cueva de las Breveritas gate. The gate lies several hundred metres of easy caving from the entrance. Beyond the entrance the cave continues to a concrete wall that blocks the passage between the Cueva de las Breveritas and Cueva de los Piquetes down flow.
We finally emerged from Cueva de las Breveritas at about 2am; the trip had taken about 5 hours and is truly great fun. It is believed that we were the first British party to have carried out this traverse, which is the longest in a lava tube cave outside of Hawaii.
A return trip was made the next day into the Sobrado section as the show cave was closed. This allowed us to take some photos and explore more of the upper series in a vain attempt to find the elusive lower level 'Galeriá de los Ingleses'.
Cueva de Felipe Reventon
This 3km long cave is in reality part of the Cueva del Viento system, but as yet no passable connection between the two has been found. The entrance is securely gated and the key (singular!) is held in the Cueva del Viento visitor centre. Permission to visit the cave is extremely difficult to arrange unless you are known to the Benishare group.
To say that the cave is securely gated is a huge understatement. Firstly a nasty crawl underneath spiky vegetation is required to even get to the wide entrance arch. Once inside a narrow passage leads off the bottom of the entrance chamber where the gate is located. The lock is located inside the gate, which is solid except for a 100mm hole through it at the hinge end. In turn the lock and bolt is hidden under a loop of steel. Thus to open the gate an arm has to be pushed through the hole until the elbow is on the other side, and the hand pushed under the loop of steel in order to undo the lock and retract the very stiff bolt. Sounds easy doesn't it - it took us over an hour and a half!
Once inside, trying not to think of the epic that locking the cave back up again is going to be, it is a rather fine cave. There is a large trunk passage and a number of intriguing oxbows. There are some fine lava features, and a couple of boulder chokes to negotiate. However this really is not a place for arachnophobes!
Cueva de los Pajaros
Our final outing was to Cueva de los Pajaros high up in the pine forests on the flank of Teide. It required an exciting off road drive that would have really upset the car hire company if they had seen what we did with their vehicle! The cave is very different from those around Icod, consisting of several hundred metres of a single very large trunk passage. In all a fine end to a great weeks caving.
Simplified survey of the Cueva del Viento system showing the main entrances
Mendip Caving Group. UK Charity Number 270088. The object of the Group is, for the benefit of the public, the furtherance of all aspects of the exploration, scientific study and conservation of caves and related features. Membership shall be open to anyone over the age of 18 years with an interest in the objects of the Group.