Towering above the north end of Machu Picchu is this steep mountain, often the backdrop to many photos of the ruins. It looks a bit daunting from below, but while steep, it's not an unusually difficult ascent, and most reasonably fit persons should be able to make the ascent in about 45 minutes. Stone steps are laid along most of the path, and in the steeper sections steel cables provide a supporting handrail. That said, expect to be out of breath, and take care in the steeper portions, especially when wet, as it can become dangerous quickly. There's a tiny cave near the top that must be passed through, it is quite low and a rather tight squeeze. Take care at the peak, it can be somewhat precarious, and those afraid of heights may want to hang out just below. The entire walk is through beautiful landscape, and the views from the top are stunning, including birds eye views over the whole site. There's also a few ruins near the top. If visiting these ruins, you'll see a second way to start making your descent down the mountain via a cave once thought to be the Temple of the Moon, along some very steep and shallow steps... these steps are a bit dangerous if wet, but the hike may be well worthwhile. This hike is one of your best bets for getting away from Machu Picchu and Huayna Picchu crowds. Tickets to Huayna Picchu have to be reserved beforehand and are limited to 400 a day - ask the tour company with which you are going to Machu Picchu to reserve this for you (at least a month beforehand). Tickets are purchased in one of two groups: 7-8am and 10-11am. 200 people are allowed in each group. Entrance to the hike is controlled by a second ticket booth, and visitors are staggered across their hour entry. In other words, if you have a ticket for the 7-8am group, even if you arrive at 6:30am, if there are other people ahead of you in line, you will have not be able to ascend until everyone in front of you has been admitted. To find this second gate, enter the site via the regular gate and follow signs.