Peru (Cusco & Machu Picchu)

Cusco sits at about 3,400 m - higher than most European ski resorts, and altitude sickness is the single most common way this trip goes wrong. Plan two easy days on arrival: no alcohol, lots of water, light food, coca tea, and nothing strenuous.

A smarter alternative: fly into Cusco and go straight down to the Sacred Valley (Urubamba/Ollantaytambo, around 2,800 m) for the first two nights, then come back up to Cusco already acclimatised. Machu Picchu itself is lower than Cusco at 2,430 m, so it feels easy by comparison.

Entry is by timed ticket on a numbered circuit, capped daily and frequently sold out weeks ahead in high season: buy as soon as your dates are fixed. The classic postcard view is on the upper circuits; the add-on climbs of Huayna Picchu and Machu Picchu Mountain are separate, limited tickets bought at the same time.

Most people take the train from Ollantaytambo to Aguas Calientes (1.5 hours, spectacular), then a shuttle bus up the switchbacks. Staying overnight in Aguas Calientes buys you the first entry slot of the morning, which is worth a lot.

For trekkers, the Inca Trail (4 days) requires a licensed operator and a permit released months in advance and gone almost immediately: book roughly six months out. The Salkantay trek is the standard alternative: higher, wilder, no permit lottery. Both close in February for maintenance.

Cusco is a genuinely great city. Inca foundation walls with colonial churches built on top, the Qorikancha, San Blas's artisan lanes and the San Pedro market. The ruins above town at Sacsayhuamán show masonry that still defies explanation.

In the valley: Ollantaytambo (a living Inca town and fortress), Pisac (terraces and a market), Moray's concentric agricultural terraces and the Maras salt pans. Two full days here is the minimum.

Add-ons if you have time: Rainbow Mountain (very high, very cold, half the day is the altitude), Lake Titicaca via Puno, or the Amazon at Puerto Maldonado for a completely different climate.

Peruvian food deserves a day in Lima on the way through: ceviche, Nikkei and some of the world's best-rated restaurants. In the highlands, expect cuy, alpaca, rocoto relleno, hundreds of potato varieties and chicha morada.

May to September is the dry season and the right window: clear mornings, cold nights, most reliable trekking. November to March is the wet season: green, cheap, quieter, but with real chance of cloud over the ruins and landslide disruption; February is the wettest month and the Inca Trail is closed.

With another week, head south from Lima into the desert. Huacachina is a tiny oasis town ringed by sand dunes, best for a sunset sandboarding session and a night under stars. Continue inland to the Nazca Lines, where the ancient geoglyphs are best seen from a light-aircraft overflight; a viewing tower is cheaper but less convincing. Round it off with Arequipa, a white-stone colonial city beneath three volcanoes, and the nearby Colca Canyon, one of the deepest canyons on Earth and a reliable place to watch Andean condors riding the morning thermals.

For a completely different side of the country, add the Peruvian Amazon. From Puerto Maldonado, a short flight from Cusco or Lima, you can stay in a jungle lodge and walk the canopy walkways. The more remote option is Iquitos, reachable only by air or river, with deeper rainforest access and pink river dolphins. Together these extensions turn a Cusco-focused trip into a genuine 2-3 week sweep of Peru's landscapes.