Be aware that you can only enter Machu Picchu with a pre-purchased ticket, and that you must provide a passport for both purchase and admission. The entrance fee to the ruins is 152 PEN, which equals roughly US$47. You must pay in soles. If you're staying in Cusco, then you can buy a ticket from the National Cultural Institute (INC) off of the main square. Once you arrive in Aguas Calientes, you can also buy a ticket at the Machu Picchu Cultural Center near the central plaza. The ticket counter in Aguas Calientes is open from 5:15 a.m. to 7 p.m. and charges additional fees. You can purchase tickets for transportation to and from the park entrance gate. This can be a great option if you want to avoid an hour-plus walk up to the ruins.