Cusco sits at roughly 3,400m (11,152ft), which makes it one of the highest major cities most travellers ever visit. The old Inca capital’s thin air shapes everything from how you sleep the first night to what you can safely do on day one.
Altitude sickness is the main hazard. Headache, nausea, dizziness and fatigue are the common signs, and they land hard on travellers who fly in directly from sea level. Give yourself a day or two in the city before anything demanding. Drink more water than you think you need, go easy on alcohol, keep meals light. Coca tea is standard local practice and helps most people.
The upside: Cusco rewards slow days. The viewpoints at Sacsayhuamán and Cristo Blanco look over the whole valley, the colonial centre and Inca stonework overlap in the same walls, and the air is bright. From here it’s a short step to the Sacred Valley and Machu Picchu, both at lower altitude — handy if Cusco wears you out.
For a packaged entry that factors altitude into the pacing, Peruways builds Cusco plus Sacred Valley plus Machu Picchu as one itinerary rather than three separate bookings.
