I thoroughly recommend the 5 day Salkantay Trek. I'm a 55 year old retired teacher, and I thought it might be a little tough for me. I did the trip with my daughter, and we were part of a group of 4 people.
We chose this trip as it was available and we thought it might be a little less touristy and tougher than the Inca Trail . We were correct on both counts. David our guide was fantastic and sorted out everything with ease. Our cook provided us with amazing 3 course meals everyday with a great variety of foods. The lad looking after the horses was equally well organised and our gear and tents arrived as expected. In all the trek was better then we had expected.
Highlights were Skinny dipping in the glacial Humantay lake, the clouds clearing over Salkantay at over 4600 metres. The hot springs in Santa Teresa were a welcome treat to soothe aching limbs. The diversity of plant life along the way was fascinating, and it was good to have a guide who was knowledgeable and enthusiastic enough to explain what was what. We had geology, history and botany lessons along the way.
Machupicchu was probably the most interesting ruin I have come across so far, and climbing up to it in the dark made it even more mystical, David gave us an excellent tour on the last day. Climbing Huaynapicchu and the surrounding view finished off a wonderful trek.
Thanks for a great trip.