This great little red book seems to be the book of choice for hiking on Tenerife. The half dozen people we chatted to on our hikes last week all had a copy (though some had the German 2007 version). The book provides a lot of variety, in terms of easy/short to challenging/hard. The author is a bit of a power walker and his times are accurate for quite fit walkers. The only caveats are that occasionally things are a bit lost in translation (the German version is the original), which just requires you to pause for a moment and re-read the instructions. Also, as with any book, things change. So, the cairn or sign marking where to turn right may have been prominent in 2001 but may be gone now. Again, this added a few minutes to our journey but it was soon obvious and easy to retrace our steps. Incidentally, walk 24 now requires you to book in advance (unless you're lucky) and pay 2 Euros. Walk 49 (Teide) requires a (free) permit (for the final ascent to the summit), which you can get via email 7 days in advance. The hikes cover a lot of the island and as the weather can be 'four seasons in one day', depending on where you are, that's great for making spontaneous decisions on the day about where to hike. Oh, and if I had a pound for each time the author uses phrases like 'wildly romantic' or 'serpentine path'... :-). Buy it, use it lots and have a great holiday - I'd love to have spent another week there hiking.