Machu Picchu sits at 2,430 metres (7,970 feet). That is high enough to notice if you fly straight in, but — and this is the part most guides bury — it is actually lower than Cusco at 3,400 m, where most people spend their first night.
If your itinerary is Lima to Cusco to Machu Picchu, give yourself at least two nights in Cusco before the train. Your worst day for soroche is usually the second, so plan the citadel visit for day three or four, not day two.
Symptoms are predictable: headache, poor sleep, mild nausea, shortness of breath on steps. Hydrate aggressively, skip alcohol, eat light, and consider sorojchi pills from any Peruvian pharmacy.
Once you are at the ruins, the altitude is manageable but the terrain is not flat — the main circuits involve a lot of stairs, so pace yourself and take breaks on the terraces.
Peruways can bundle acclimatisation stays, trains and timed-entry tickets so the pacing is already built in.
