Annapurna Circuit (Nepal)
"The mountain walkers' mountain walk" circles Nepal's Annapurna massif with its six mighty peaks of over 7,000 metres. The three-week trek starts in lowland farming country at Besi Sahar and climbs gradually to the formidable pass of Thorung La at nearly 5,500 metres. Do the circuit in spring to see the rhododendron forests in full and spectacular bloom.
Exodus runs 23-day trips from £1,399 to £1,699 per person including flights from London to Kathmandu and accommodation in tea-houses (0845 863 9600; exodus.co.uk).
Bering Strait (Arctic)
The stretch of water separating Alaska from Russia may once have been a land bridge by which humans crossed from Asia to North America, but is now an unpredictable channel, 85km wide, clogged with ice in winter. Rewards for those who travel here are sightings of polar bears, walruses and migrating seabirds, as well as the opportunity to meet the Chukchi people who inhabit this harsh environment.
Arcturus Expeditions has a 16-day trip, departing from London on 11 August, for £5,880, based on a shared, triple cabin (01837 840640; arcturusexpeditions.co.uk).
Chihuahua–Pacific Railway (Mexico)
This spectacular, winding track across the Sierra Madre links the northern Mexican city of Chihuahua with Los Mochis on Mexico's Pacific Coast. The whole trip takes 15 hours but you must stop off half-way at Divisadero for thrilling views down into Copper Canyon. A single ticket from Chihuahua to Divisadero costs 1,089 pesos (£55); all the way to Los Mochis, 1,981 pesos (£100).
Journey Latin America offers a four-day Copper Canyon trip for £475 with overnight stays in Divisadero and Creel. The company can also book good-value flights. (020-8747 8315; journeylatinamerica.co.uk).
Drake Passage to Antarctica
Named after its discoverer, Sir Francis Drake, and renowned for its wild storms and choppy seas, the 800km strait connects the Atlantic and Pacific Oceans. It's also the shortest sea crossing between South America and Antarctica, where the visitor will find penguin rookeries, seals, whales and ,of course, icebergs . Gap Adventures runs an 11-day cruise leaving the Argentinian port of Ushuaia on 5 Nov 2010 for £3,309 per adult, excluding flights from UK to Ushuaia, via Buenos Aires (08444 10 10 30; gapadventures.com).
Ebro route (Spain)
Spain's ambitious long-distance footpath, the Camino Natural del Ebro or GR99, follows the course of the River Ebro for nearly 1,300km from the Cantabrian mountains to the Mediterranean. There are 42 day-stages, including rugged mountain terrain, the vineyards of La Rioja and finally the rich wildlife of the delta. Visit chebro.es for downloadable guides (in Spanish); topographic maps and guide book (in Spanish) available from Stanfords for £18.95. Santander and Bilbao are the nearest airports for the start of the Ebro trail, Zaragoza for the middle sections. Cyclists can also use the trail.
Iberocycle (00 34 942 58 10 85; iberocycle.com ) runs eight-day tours along the La Rioja section for €835 (£740) per person, based on two sharing, plus €88 for bike hire. Next tour starts 18 April.
Freedom Trail – South Africa
Known as "the soul of mountain biking", the Freedom Trail is a 2,300km mountain bike trail between Durban and Cape Town. It crosses lush forests in the Baviaanskloof, the sparse semi-desert of the Southern Cape and the grasslands of Natal. The whole route, best in spring and autumn, will take about six weeks or you can choose a section. Information about the stages (50km to 80km), booking for food and accommodation (R450/£38 per night) and downloadable maps are on the Freedom Challenge website freedomchallenge.org.za ; call 00 27 84 567 4152 for more information.
Guided tours can be arranged with Cape Town-based Daytrippers (00 27 21 511 4766; daytrippers.co.za).
Great Ocean Road (Australia)
This seaside highway meanders for 250km along Victoria's ruggedly beautiful south-east coast between the cities of Torquay (90km south-west of Melbourne) and Warrnambool. Stop off to enjoy the views and splendid beaches as well as some of Australia's best rainforest scenery in the Otway Ranges. Most striking of all are the rock stacks, known as the Twelve Apostles, that rise out of the Southern Ocean. More information from visitvictoria.com , or the definitive book on the subject: Richard Everist's Australia's Great Ocean Road: the complete guide to southwest Victoria (£19.99)
Wildlife Tours Australia offers a day trip by coach along the Great Ocean Road for A$95 (£55), setting out from Melbourne (00 61 3 9396 1938; wildlifetours.com.au ).
Highway 1 (US)
State Route 1, as it is officially known, hugs California's scenic Pacific coast for 800km between Capistrano Beach, south of Los Angeles, and Leggett, north of San Francisco. Given the accolade of All American Road, it takes in the hectic cities of San Francisco and California as well as the magical landscape of Big Sur. You can't rush the trip – local speed limits will ensure that – but there's much to see and, in places like Monterrey, good food to be enjoyed. Accommodation should be reserved during the busy summer months, though quieter, fog-free September V C and October are better months for the trip. If you can afford to rent a convertible, this is the time to do it.
Virgin Holidays has fly-drive holidays to San Francisco from £662 per person in April (0844 557 5825; Virginholidays.co.uk ). You could easily combine Highway 1 with the John Muir Trail, below.
Inca Trail (Peru)
Splendid as the sites and views may be along the demanding, high-altitude path built by the Incas, it's arriving at the breath-taking, ancient city of Machu Picchu that is the icing on the cake. Independent trekking is prohibited, so you need to arrange your trip, which takes four days, with a trekking company. Following recent floods, the trail is not scheduled to re-open until 1 April. The best period for the trip is May to September; due to limits on available permits, book at least four months in advance. Find independent guidance on the Trail at incatrailperu.com .
Peru Treks provide a package leaving from Cuzco, including permits, for US$465 (£310); (00 51 84 222 722; perutreks.com ).
John Muir Trail (US)
This epic two-week trek through Californian wilderness takes in Yosemite, Kings Canyon and Sequoia National Parks, 11 high passes, gorgeous waterfalls and not a single road. You need to carry your own tent and enough food for 10 days and to be prepared for greedy bears and marmots as well as altitude sickness. Independent trekkers should apply for the essential entry permit ($5/£3.20) up to six months in advance. Comprehensive information can be found at the website besthike.com/northamerica .
Sierra Mountain Center offers 20 day guided treks (one guide to five trekkers) which include permits, tents and food for $2,995 (£2,000). The next trip begins 5 July (001 760 873 8526; sierramountaincenter.com ).
The highest "walkable" mountain in the world rises from the surrounding plains to just under 6,000 metres. Although Chris Moyles and other celebrities recently climbed Kilimanjaro for charity, the physical demands of hiking at such an altitude are considerable. Among the several ways to the summit, the Rongai route is best for people who are not confident of their fitness.
Africa Travel Resource has one-week group trips available from June to November. The price is $2,055 (£1,332) excluding flights (01306 880 770; africatravelresource.com ).
Lycian Way (Turkey)
The Lycian Way is a 500km coastal waymarked trail over footpaths and mule tracks from Fethiye to Antalya in southern Turkey. Spring or autumn are the best times to walk it and enjoy the 12km long beach at Patara, the fabulous ridge-top walk to Finike and a stay at the lighthouse at Cape Gelidonia. Information is available online at lycian way.com.
Inntravel has added a nine-day section of the walk to its 2010 portfolio. The first available departure is 1 April and costs £798 including accommodation, meals and transfers from Antalya airport, but not flights (01653 617002; Inntravel.co.uk ).
Mekong River cruise
From its source in Chinese-occupied Tibet, the sinuous Mekong crosses China, Thailand, Burma, Laos and Cambodia before reaching the South China Sea via its delta in Vietnam. The attractions of South-east Asia's longest river, much of which is navigable, include floating villages, temples and an extraordinary profusion of fish species. For a taste of traditional river life on a river barge between the Laotian towns of Houeisai and Luang Prabang, Asian Oasis (00 856 305 258 436 asian-oasis.com ) provides a two-day package for US$267 (£175), based on two people sharing. Alternatively you can cruise upriver from the populous delta via Phnom Penh with its chilling Genocide Museum and finish at the extraordinary temple complex of Angkor Wat.
Steppes Travel operates eight-day cruises (upstream or downstream) most months of the year, costing £2,470 including flights from London (01285 880 980; steppestravel.co.uk )
Nile Cruise (Egypt)
The Nile, reckoned to be the world's longest river at 6,695km, passes through eight countries besides Egypt on its way to the Mediterranean. But it's Egypt - and particularly its ancient civilisation – that is most associated with the river. In the easily navigable section below Aswan are the spectacular Edfu Temple and the Valley of the Kings (with Tutankhamun's tomb) as well as the vibrant city of Luxor. Many tour operators offer cruises which take in these sights.
Thomas Cook has a one-week cruise on the 70 cabin MS Semiramis 2 for £621 (based on two sharing, with online discount) departing Manchester on 14 April; Gatwick is £51 more expensive (0871 895 00 55; thomascook.com ).
Otago Rail Trail (New Zealand)
Based on a former railway line, the Otago Rail Trail runs for 150km from Clyde to Dunedin on New Zealand's South Island, taking cyclists through spectacular landscapes of mountain ranges, hills and gorges, across the vast Maniototo plain, through old gold mining towns and, ending amid the fruit-growing areas of Central Otago. For more information, visit otagorailtrail.co.nz .
Trail Journeys of Clyde will rent you a mountain bike for NZ$35 (£16) per day and also provides an all-inclusive, guided four-day tour (00 64 3 449 2150; trailjourneys.co.nz ).
A trip through the 80km canal, considered one of the great engineering triumphs of the 20th century, involves being lifted up to the Continental Divide and then lowered back down to sea level by three huge locks. Aside from the engineering feats, you can also appreciate the rainforests that border the canal and the islands filled with wildlife on Gatun Lake.
Panama Marine Adventures operates monthly full transits of the V C canal that take about nine hours (next trip: 20 March; $165/£110) and more frequent partial trips of four to five hours ($115/£78) (00 507 226 8917; pmatours.net ).
The transit is also part of a number of cruise itineraries. Virgin Holiday Cruises has a package from £1,099 (12 nights, full board, with an inside cabin) leaving Heathrow on 25 April (0871 781 9877; virginholiday s cruises.co.uk ).
Q tour, Torres del Paine (Chilean Patagonia)
Torres del Paine is a Unesco World Biosphere Reserve, as well as one of the most pristine and remote places on earth. It is a three-hour bus journey north of Punta Arenas, on the Straights of Magellan, which claims to be the world's southernmost city. The park's so-called "W" trip is the easier path but its "Q"circuit provides an unequalled wilderness experience whose highlight is the three twisted granite towers that give the Park its name.
Chilean firm Erratic Rock provides a 10-day camping package including local transfers, in groups of up to 10 trekkers, starting from US$1,750 (£1,167) (00 56 61 414 317; erraticrock.com ).
Royal Scotsman (Scotland)
Conflating the names of two great Anglo-Scottish trains – the Royal Scot and the Flying Scotsman – this is now the Scottish operation of the Orient Express group. As you might expect, it is an unashamedly luxurious tour of the Highlands and Lowlands on little-frequented railway lines. Apart from views of the lochs, glens and waterfalls from armchairs in the observation car, there are visits to a distillery, clay-pigeon shooting and tours of estates and castles on offer. The train stops at night so the 36 passengers can sleep soundly in their private compartments. The price matches the luxury: the four-night "classic journey" costs £3,720 per person based on two sharing.
The next trip leaves Edinburgh on 10 May (0845 077 2222; royalscotsman.com ).
The original Silk Road was actually a system of trade routes linking China with the Mediterranean and got its name from the most valuable import from the east. The whole route was about 80,000km long. Along the stretches which can be travelled safely are some extraordinary sights, including the terracotta warriors at Xian, an enormous Tibetan monastery at Labrang and the city of Samarkand.
World Expeditions offers a 28-day, small-group adventure holiday between Beijing and Tashkent, including rail and vehicle transfers, accommodation and meals, but excluding flights from the UK, for £2,950. Next departure is 8 April (0800 074 4135; worldexpeditions.com ).
The world's greatest railway line crosses much of Russia from Moscow to the eastern port of Vladivostok. The 9,000km railway which links Europe with the Pacific crosses seven time zones on its one-week journey. As of this month you can cross the Volga, marvel at limpid Lake Baikal and get a tantalising taste of the trip, all from the comfort of your desk ( www.bit.ly/Transib ). For the real thing, one-way fares start at around 13,000 roubles (£280) in a four-berth sleeper or twice as much in a two-berth sleeper. A number of companies organise trips that use the Trans-Siberian for much of the distance but then branch south across Mongolia to Beijing.
Trans Siberian Experience has two 15-day trips a month starting from Moscow. Cost for two travelling together, excluding flights, starts at £1,565 (0845 521 2910; trans-siberian.co.uk ).
Ulster Way (Northern Ireland)
Relaunched last year, the 1,000 km Ulster Way is a circular walking route around the best landscapes in Northern Ireland. The highlight is the 50km stretch along the Causeway Coast with sandy beaches, cliff-top paths and at its heart, the geological wonder of the Giant's Causeway. Find more information at walkni.com/ulsterway .
Let's Go Walking provide packages for sections of the walk: five nights bed-and-breakfast with luggage transfer costs from £379 (01837 880075; letsgowalking.com )
Via de la Plata (Spain)
A fine alternative to the better known and much more crowded pilgrimage route to Santiago de Compostela along Spain's north coast, the "Silver Way" starts at the southern city of Seville and ends at Gijon in the north. The journey of almost 1,000km takes six to seven weeks to complete, with accommodation in refuges and small hotels along the way. The walk takes you past some of Spain's best preserved Roman remains, notably in the fine city of Merida. There's an online guide to the route at santiago.com, while Via de la Plata by Alison Raju is published by Cicerone press; £12 95).
The starting point is served by Vueling from Heathrow ( vueling.com ) and Ryanair from Stansted ( ryanair.com ); the northern end offers flights from Asturias airport to Stansted on easyJet ( easyJet.com ).
West Coast Trail (Canada)
Dramatic rocky headlands, wide, sandy beaches and lush rainforests are features of this demanding, 75km trek along the coast of Vancouver Island. The West Coast Trail, which was originally built to assist the victims of the area's frequent shipwrecks, is open for hiking from 1 May to 30 September. As bears and cougars frequent the park, all hikers must attend an orientation session before attempting the trail. A daily quota is set, so reservations are advisable.
Find maps and reservation details at westcoasttrailbc.com , or call 001 250 728 3234. The user fee is C$128 (£80). Access from the town of Victoria to both ends of the trail is easiest by bus (001 250 477 8700; trailbus.com ).
X-country skiing on the King's Trail (Sweden)
Of course it should be X for Xanadu, but that fabled destination is now just a neglected ruin in Inner Mongolia. So instead we have settled on the King's Trail: the crowning glory of cross-country skiing routes. It starts deep in the Arctic Circle, 50km north of Kiruna, a mining town in northern Sweden. Then it winds southwards for 440km to Hemaavan, paralleling the frontier with Norway. Accommodation is in mountain huts a day's trek apart.
Nature Travels runs eight-day tours along the most picturesque section of the trail between Abisko and Mount Kenekaise, Sweden's highest mountain. There are several departures in March and April, costing from £559 (excluding travel to Kiruna and ski rental) (01929 463 774; naturetravel s .co.uk ).
Yangtse cruise (China)
"As construction work on the monumental Three Gorges Dam project continues," The Independent observed in 1997, "tourists will need to be quick if they want to catch a glimpse of the historic gorges before they are submerged forever". Well, the world's largest and most controversial dam is now in place, but China's mightiest river still boasts stunning landscapes. And, in spite of some very polluted stretches it is also home to at least two critically endangered species: the Chinese Alligator and the Chinese Paddlefish.
Archers Direct offers a 15-day tour of China, of which four days is spent cruising the Yangtse, costing from £1,859 per person, available from 16 April (0844 573 4806; archersdirect.co.uk ).
Zambezi whitewater rafting (Zambia and Zimbabwe)
The Zambezi crosses six countries on its way to the Indian Ocean but the most eye-catching part is the 500km stretch where it acts as the border between Zambia and Zimbabwe. Before spreading out across the plains on its way to the Kariba Dam, the river hurtles over the Victoria Falls and is then funnelled into the Batoka Gorge, whose rapids and whitewater have made it a prime spot for adventurous rafting. Operators are based in Livingstone or Victoria Falls.
Shearwater Adventures organise five-day rafting and camping packages between August and mid-January, starting from Victoria Falls. The cost is US$620/£401 per person, excluding air fares and visas (00 263 13 44471; shearwateradventures.com ). The closest big airport is Lusaka in Zambia, served by British Airways.