I took my 12-year old grandson on the Denali Zipline Adventure. The guides, (Molly and Reed) were wonderful and were very attentive to him. They were thorough with their instructions but did it all with a wonderful sense of humor to keep everyone relaxed. I would most certainly recommend this adventure. It was listed as strenuous, but I am 75 years old and did not find it too difficult. My only complaint was that the pictures they took to sell to us were not good. They were low resolution so do not post well online, and I had to buy all of the pictures they took instead of choosing only those I wanted.