You'll go up there especially to watch the sanctuary of Machu Picchu from a different perspective. Culminating at 2720 m altitude, you will dominate the Machu Picchu about 360 meters. The ascent is not impossible but rather complicated and physical. Ideally, choose a niche where there are few people (rather early in the day). Going around is of course more interesting but longer than a round trip. But the return is painful or even dangerous when the small path is very busy. For this, and to preserve the integrity of the site, that the authorities have restricted access to two groups of 200 people per day.