Extraordinary, but not for everyone - I was very impressed with the guide, John. He is a biologist who specialises in freshwater conservation and he is extremely knowledgeable about all the local species. He can recognise all the birds by both sight and sound and name them in English, Spanish and Latin. He can even imitate most of them to get them to come closer! He has some great stories about the traditional botanical uses of the plants and conservation efforts in Colombia. I also felt very safe with him in an area where it’s easy to get lost far from help - he has been trekking in the park for >15 years - and he was generous enough to carry my bag as well as his when I was struggling. The landscapes are stunning, many of them endemic to this region of Colombia, and you will see some extremely rare fauna and flora. The day I went we even caught a (very brief) glimpse of a puma. The accommodation is very basic but offers steaming hot showers, nourishing meals and a great atmosphere (the second one was hosting a party for all the farmers in the area which was a lot of fun). Also some cute baby farm animals. However, this experience is definitely not for everyone. First day is 1000m ascent over 11km (plus a lot of up and down which makes it more). Second day is 500-1000m and 10-14km depending which option you choose. Third day is another 14km. It is all at high altitudes and you will experience all extremes of tropical heat, sub zero nights, strong winds and the moisture of being inside a cloud. I am probably above average fitness (31f, exercise c. 6 hours a week, no serious health conditions) and there were definitely points when I felt ill and wasn’t sure if I could complete it. Also met some stronger younger men who admitted they were pretty exhausted. The ‘trail’ is often just clambering up rocks in the middle of a river or walking over wobbly logs/badly maintained bridges above deep canyons, and the standards of hygiene at the farms are far from what we’d expect in a modern urban environment. Also there is a long distance between farms so some days you might go c. 8 hours with only small snacks to eat. Overall though, an extraordinary experience. If you are in good physical condition, up for a challenge and love stunning scenery, birds and plants, this is unmissable.