The tour itself was interesting and informative. It was inevitably a little slow because of the dual English/Spanish group, but the quality of the English translation was good. I did have some issues with tickets though. I had booked the tour while already on holiday and had been unable to print out my ticket in advance (I downloaded it to my mobile instead). The guide was not impressed and shouted at me in front of the other guests before eventually granting me permission to join the tour that I had paid 21 euro for. To be fair it does state that you must have a printout, so I'll know next time not to book any tours that do not allow digital tickets!

This is a must see tour. It is very high up and sunny, so sun protection recommended, but cool in the shade. Fantastic views from coast to coast and other islands. Enthusiastic and knowledgable staff gave great lectures and let you look at the sun safely through solar telescopes. There is also a short lecture inside and a walk around many different telescopes. Hugely enjoyable.

Had a nice tour with a great guide who was funny but also very proud of the work that he and his colleagues performed. Also interesting is the fact that this facility studies the sun which is not very common and get's no money from the government. Jacket and hat is not optional, but necessary as it is quite cold on top. The rest you will need to fond out yourself

The tour was good, with a very knowledgable guide. Pointed out many parts of the site and the work being carried out by scientist's. It would have been an excellent recommendation if a large telescope could have been available for use.

Really enjoyed this tour. Good and knowledgeable guide who took time to answer any questions and explain who used the facilities and what they were. We'll go back another time to repeat it in the evening to see the stars!