The difficulty of the different hiking trails to Machu Picchu varies greatly:
The Inca Trail: The most famous hike to Machu Picchu is moderately challenging. The Inca Trail is a 4-day, 26-mile (43 km) hike that takes you through some of the most beautiful scenery in the Peruvian Andes. The trail is not for the faint of heart, as it involves a lot of uphill climbing and reaches an altitude of over 13,800 feet (4,200 meters).
The Salkantay Trek: Salkantay is another popular pick, but it is considered to be the most difficult one due to the rugged terrain and significant altitude change. The Salkantay Trek is a 5-day, 32-mile (51 km) hike that takes you through the Salkantay Valley, past snow-capped mountains, turquoise lakes, and lush rainforests.
The Lares Trek: A good option for those who are looking for a shorter and less challenging hike. The Lares Trek is a 4-day, 23-mile (37 km) hike that takes you through the Lares Valley, past traditional villages, and glacial lakes.
In addition to these hikes, you can also take a bus or train up to Machu Picchu from the town of Aguas Calientes, or explore beginner-friendly Machu Picchu tours from Lima.