The longest mountain range on earth, running the length of a continent, with the altitude that shapes every decision you make about travelling in it.
What it is
4,300 miles of mountains down the western edge of South America, through Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile and Argentina. The longest continental range on earth, with about a hundred peaks over 6,000 metres and a chain of high plateaux — the altiplano — where people have lived for thousands of years at heights most visitors find difficult for a week.
Travelling the Andes means travelling high. Quito sits at 2,850m, Cusco at 3,400m, La Paz at 3,600m, Potosí at 4,090m. These are not viewpoints; they are cities where hundreds of thousands of people live ordinary lives, and arriving in one from sea level is a physiological event.
Altitude, honestly
Above about 2,500m most people feel something: breathlessness on stairs, a headache, broken sleep, no appetite. That is normal acclimatisation and it passes in two or three days.
What matters is knowing the difference between that and altitude sickness, which gets worse rather than better and is dangerous. The rule is simple and non-negotiable: if symptoms worsen, descend. Nothing — not a booked trek, not a flight, not a paid permit — is worth ignoring that.
Practical measures that work: arrive and do nothing for 48 hours. Ascend gradually where you can — the bus from the coast beats the flight into Cusco. Drink far more water than feels necessary. Skip alcohol for the first days. Coca tea helps mildly and is legal and ubiquitous in Peru and Bolivia. Acetazolamide works and is worth discussing with a doctor before you fly.
Sleep altitude is what counts, not the highest point you reach in a day.
The seasons, which run in two directions
The tropical Andes — Colombia, Ecuador, Peru, Bolivia — have a dry season from roughly May to September and a wet one from November to March. Dry season is when the treks are open and the views exist; it is also cold at night and busy.
Patagonia, at the southern end, is the reverse: November to March is its summer, and the rest of the year most of it closes.
That opposition is the single most important planning fact about South America. A trip that takes in both Peru and Patagonia is really two trips, and doing them in one southern summer means Peru in its wet season or Patagonia in its winter.
The classic routes
The Gringo Trail runs Lima → Cusco → Lake Titicaca → La Paz → Uyuni → Atacama, and it exists because those places are genuinely extraordinary and the buses connect. Two to three weeks.
Ecuador’s Avenue of the Volcanoes — Quito south through Cotopaxi and Baños to Cuenca — is a compact, high, spectacular week and far less travelled than Peru.
Colombia’s Zona Cafetera and the Cocora Valley are lower, greener and easier, and Colombia has become one of the region’s most rewarding countries in the last decade.
The Carretera Austral and the Torres del Paine circuit are the Patagonian end, and both need a southern-summer booking made months out.
Getting around
Long-distance buses are the backbone and are better than their reputation — the premium overnight services in Peru, Chile and Argentina have flat beds and are a reasonable way to cover distance.
Internal flights save days across a continent this size and are not expensive in Peru or Colombia. Note that flights into high cities are frequently disrupted by weather.
Roads are mountain roads. Journey times on a map are optimistic by a wide margin.
What it costs
Bolivia and Peru are among the cheapest countries in the Americas to travel in. Chile and Argentina are considerably more expensive, and Argentina’s currency situation has made pricing volatile in a way that changes what advice is even useful — check current conditions rather than a figure from a guidebook.
Trekking permits are the big fixed cost. The Inca Trail is capped, licensed-operator-only, and books out six months ahead.
What people get wrong
Trying to do too much. The distances are continental — Lima to Cusco is a two-hour flight or twenty hours by bus — and the altitude means you move slower than you plan. Three countries in two weeks is a plan that produces a fortnight of bus stations.
More Regions
Southeast Asia
The region that taught a generation how to travel cheaply and is still the easiest place on earth to do it. Warm, connected, and far more varied than the circuit suggests.
East Africa
The Serengeti and the Mara, Kilimanjaro, the Rift Valley lakes and the Swahili coast — and the safari industry that sits on top of all of it.
The Mediterranean
Twenty-two countries around one sea, with three thousand years of everybody conquering everybody else layered into the same towns. The easiest great region to travel and the hardest to see freshly.