If you go to Peru you must do this trip: the Inca Trail .
This agency is very serious and precise. When you arrive at the airport of Cusco they arrive to take you to your hotel and then they come back the beginning day of the trip. Four spectacular days. You are in the nature without any technology or similar, only you, the mountain and nature and other good people in your group.
The guides are amazing, precise and always ready to help you. The porters are a very important part of the group and also the chef because the food is very very good and different each day. An adventure to do.