Best hikes in the world

Work backwards from the constraint you cannot move. If your dates are fixed, filter by season first: the Alps are only reliably walkable July to September, Nepal is best October to November and March to May, and New Zealand's Great Walks run November to April. If your budget is fixed, filter by country next: Nepal and Peru are cheaper on the ground than Switzerland or the United States.

Then check the permit. The Inca Trail, Milford Track, John Muir Trail and West Coast Trail all cap numbers, and the popular dates sell out months ahead. A route with no permit but bookable huts, such as the Tour du Mont Blanc, is easier to plan late but harder to plan cheaply, because hut beds go early too.

Finally, be honest about altitude. Everest Base Camp and Kilimanjaro both put you above 4,000 m, where a proportion of fit people still get sick. A route that stays low removes that variable.

Budget for three buckets: getting there, the trail itself, and the days either side. The trail bucket is the one people underestimate. On guided routes such as Kilimanjaro, the operator fee covers park fees, guides, porters, food and huts, and it is the single biggest line. On self-guided routes such as the Tour du Mont Blanc, you pay per hut night plus meals, which adds up fast in Switzerland.

Add contingency days. Weather, altitude and transport delays all cost money, and a missed permit date is usually non-refundable. Travel insurance that covers hiking and evacuation is not optional on the high routes; check the altitude limit in the policy wording before you buy.

Altitude is the most common reason a hike ends early. Symptoms of acute mountain sickness, such as headache with nausea and poor sleep, usually improve with rest and descent, but they can worsen. Ascend slowly, take the acclimatisation day, and turn around if you feel worse rather than better.

Permits and closures move. Trails close for landslides, fires, rockfall and maintenance, and quotas change year to year. A booking confirmation is not a guarantee the route will be open on your date. Check the park authority's own page in the week before you travel, not a blog post from three years ago.

Guides are mandatory on some routes and strongly advised on others. On Kilimanjaro and the Inca Trail you cannot walk independently. On Everest Base Camp you can, but a licensed guide or porter is common and useful. On the Tour du Mont Blanc you can walk alone, but book huts regardless.

The table below puts the eight routes side by side on the things that decide a booking: days, altitude, independence and cost band. Use it to shortlist two, then check permits and flights for those two only.

1. Choose your dates and check the season window for your shortlist. 2. Check the permit or booking system and note the release date. 3. Book the permit or hut first, then flights. 4. Arrange insurance that covers your maximum altitude. 5. Train with your actual pack on consecutive days. 6. Re-check trail status and weather in the final week.