The Inca Trail to Machu Picchu (also known as Camino Inca or Camino Inka) consists of three overlapping trails: Mollepata, Classic, and One Day. Mollepata is the longest of the three routes with the highest mountain pass and intersects with the Classic route before crossing Warmiwańusca ("Dead Woman's Pass"). Located in the Andes mountain range, the trail passes through several types of Andean environments including cloud forest and alpine tundra. Settlements, tunnels, and many Incan ruins are located along the trail before ending the terminus at the Sun Gate on Machu Picchu mountain. The two longer routes require an ascent to beyond 3,660 metres (12,010 ft) above sea level, which can result in altitude sickness.
Concern about overuse leading to erosion has led the Peruvian government to place a limit on the number of people who may hike this trail per season, and to sharply limit the companies that can provide guides. As a result, advance booking is mandatory. A maximum of 500 people, including guides and porters, are permitted to begin the trail every day. As a result, the high season books out very quickly.
The trail is closed every February for cleaning.
Trekkers normally take four or five days to complete the "Classic Inca Trail" but a two day trek from Km 104 is also possible.
It starts from one of two points: 88 km (55 miles) or 82 km (51 miles) from Cuzco on the Urubamba River at approximately 2,800 metres (9,200 ft) or 2,600 metres (8,500 ft) altitude, respectively.
Both of these trail segments meet above the Inca ruins of Patallacta (sometimes called Llactapata), a site used for religious and ceremonial functions, crop production, and housing for soldiers from the nearby hilltop site of Willkaraqay, an ancient pre-Inca site first inhabited around 500 BC. The trail undulates, but overall ascends along Rio Cusichca (aka River Kusichca or "happy river").
At the small village of Wayllabamba the trail intersects with the "Mollepata Trail" at 3,000 metres (9,800 ft).
Small, permanent settlements are located adjacent to the trail, and Wayllabamba has approximately 400 inhabitants (130 families) spread along this portion of the trail. Peru Hostel, Cusco: Pack animals—horses, mules, donkeys, and llamas—are allowed.
At Wayllabamba the trail to Machu Picchu turns west and begins ascending along a tributary of the Cusichaca. Because of previous damage caused by hooves, pack animals are not allowed on the remainder of the trail. For the same reason, metal-tipped trekking poles are not allowed on the trail.