Enjoy the road. They say that the journey sometimes matters as much as the destination and curiously is the case now, since the ascent from Machu Picchu to the Sun Gate is a very nice one where you can enjoy the same view that the Incas had hundreds of years ago by trails that they themselves built.
Dazzle yourself with the scenery. It is a privileged view that we have from here: the Huayna Picchu mountain, the Urubamba River and Machu Picchu Pueblo along with its beautiful surroundings.
Bird watching. If you are lucky, at these heights you can find birds that usually inhabit Machu Picchu. Among them we have the chestnut-breasted hummingbird, the Andean guan, the famous cock of the rock, the blue tanager and others.
It's a route rarely visited by tourists, but it's one of the best scenic routes within the archaeological park.
You should definitely hike it; if you don't like walking, this isn't for you.
The path is peaceful, paved by the Incas themselves. This trail is part of the great Inca Trail known as Qapac Ñan.
The return takes three hours at a leisurely pace. This hike is meant to be enjoyed, not rushed, so take your time and don't forget to bring your water bottle and light clothing.