There is no single right answer, but there is a wrong one: assuming Peru is a country you can see in a long weekend. The distances are big, the altitude is real, and the two together decide how much you can actually fit in.

Below are three itineraries that work, and the reasoning behind each. Pick the one that matches the days you have, not the one that matches your ambition.

First, the two things that eat your days

Altitude

Cusco sits at 3,400 metres. Arriving from sea level and going straight into activity is how people lose a day to a headache instead of gaining one.

Budget two nights in Cusco before anything demanding. That is not wasted time: it is what makes the rest of the trip possible, and it is non-negotiable before any trek.

Distance

Peru is roughly twice the size of France. Lima to Cusco is an hour and a half by plane and over twenty by road. Cusco to the Amazon is another flight or a long drive.

Every region you add costs you most of a travel day at each end. Three regions in ten days means three days on the move.

7 days: Cusco and Machu Picchu, done properly

This is the shortest trip that does not feel rushed, and it is the most common mistake to try to shorten it further.

Days one and two: arrive in Cusco, acclimatise, walk the centre slowly, San Blas, the Qorikancha. Nothing strenuous.

Day three: Sacred Valley. Pisac or Ollantaytambo, at a lower altitude than Cusco, which also helps you adapt.

Day four: train to Aguas Calientes and Machu Picchu, either that afternoon or the next morning.

Days five to seven: back to Cusco, a day for Rainbow Mountain or the Seven Lagoons if you feel strong, and a buffer day before flying out.

What does not fit: any multi-day trek, the Amazon, Lake Titicaca or Arequipa. Trying to add them is what turns a good week into an exhausting one.

10 days: add a trek

Ten days is the first point where a multi-day trek stops being reckless.

Days one and two: Cusco, acclimatising. Day three: Sacred Valley, still adapting.

Days four to seven: the trek. The classic Inca Trail is four days and ends at Machu Picchu. Lares is four days and finishes with the train. The short Inca Trail is two days if you are tight.

Days eight to ten: recovery in Cusco, a spare day for weather, and the flight home.

The spare day matters more than people expect. Passes close, trains are delayed, and a plan with no slack becomes a problem the first time something slips.

14 days: add a second region

Two weeks lets you keep the trek and add one more region. One, not two.

The Cusco block stays as above: acclimatisation, Sacred Valley, trek, Machu Picchu, recovery. That is ten days.

Then choose one. The Amazon around Puerto Maldonado or Manu means three to four days and a complete change of climate. Lake Titicaca and Puno means three days and stays high. Arequipa and the Colca Canyon means three to four days and drops you to a comfortable 2,300 metres.

If it is your first time in Peru and you already trekked, the Amazon is the biggest contrast. If you want more mountains, Colca.

What about Lima?

Lima is where you land, and it deserves a day rather than none. Barranco, the Larco Museum and the food are worth an afternoon and an evening.

But do not build the trip around it. If days are short, use Lima as a connection and spend the time in the Andes.

The mistake almost everyone makes

Cramming. A fourteen-day plan with Cusco, Machu Picchu, a trek, the Amazon, Titicaca and Arequipa exists on plenty of spreadsheets and works on none of them.

Every added region costs travel days, and altitude changes cost recovery. The trips people remember well are the ones with one region fewer than they wanted and one spare day more than they thought they needed.

If you only take one thing from this: protect the two acclimatisation days at the start and the one spare day at the end. Everything else is negotiable.