The Inca Trail is the 4 day and 3 night trekking route to the Inca City of Machu Picchu. Only 500 tickets are available per day. It is recommended to make the reservation 6 months in advance. Tickets go on sale every October for the following year. If you plan to trek from April to August, you should pick your dates in September so that you can buy tickets the day they go on sale. The most popular dates sell out the day they go on sale!