Since I'm interested in focusing on other things (aside from my feet on the trail) while on a trek, I choose to hike to Ciudad Perdida in 5 days. I'm glad I did. There's so much to marvel and wonder about. I was thrilled and humbled to have made a personal connection with a young Kogui boy and his mother - priceless. Yes, the hike is challenging-you'll enjoy it more if you're in reasonable shape and walk/hike regularly. Sleeping and showering facilities are standard "backcountry". But everything is hauled in by mule and bedding is all hand laundered - makes you appreciate the efforts they go through. Pants and long sleeved shirts (especially after dark) are better then 100% deet which sweats off within 10 minutes. Don't bother with swimsuits, just "boxers"/sports bra type clothing for quick dips - works much better. Nicolas, our guide from Magic Tours was professional, knowledgeable and passionate about his country; I think I'd follow him anywhere. The trek gave us another glimpse into the heart and soul of this awesome country. His crew kept us well fed and comfortable. This trek is a must do on your Colombia trip.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.