Circuits and the clock
The citadel is split into routes. The hour on the ticket is the hour you enter.
A Machu Picchu ticket is not a general admission you can wander on. It names a circuit and an entry hour. The standard circuits stay in the citadel. Circuit 1 is the panoramic route, Circuit 2 is the classic route, and Circuit 3 is the lower, royalty route. The mountain routes are numbered off those, and they are a different product. Slots run from about 6:00 into the early afternoon. The site is open every day.
Ask, then we check
Write the circuit you want in the note. We look before you pay. If that route is gone for the hour you need, we say so and offer another standard circuit, or we do not take the booking. We will not promise Huayna Picchu because a website still shows a photo of it. Those routes have a hard cap and they sell out.
How long to allow
A standard circuit is about two to three hours on the ridge, plus the bus each way. Arrive in town with time to spare. The bus queue is part of the morning, and a missed entry hour is not something the gate repairs. The citadel is about 2,430 meters up. If you have just landed in Cusco, which is higher, do not make Machu Picchu your first morning.