Nestled into the foothills of the Himalayas, Nepal is a magnet for trekkers and a launch pad to scale the world's highest mountains.
But as the ultra-running fad gains momentum, Nepal has become a proving ground for thrill seekers drawn to its striking scenery, extensive trail network and diverse terrain. Strong competition from local running talent is an extra drawcard for the destination.
In the past three years, the number of single and multi-day running races in Nepal has almost tripled. These are not your average 10-kilometre fun runs, but real tests of endurance. New to the racing calendar last year was the Annapurna 100-kilometre Ultra Mountain, descending from Annapurna Base Camp at 4,130 metres to Pokhara at 820 metres, and the Manaslu Mountain Trail Race, a 212-kilometre race over seven days, topping out at more than 5,100 metres.
Runners say the experience in Nepal allows them to be among the mountains and get a glimpse of nature at its best. Athletes from novices to elites are taking on such challenges, says Nepalese ultra-running pioneer Ramesh Bhattachan, "some for the sake of participation, some for enjoyment, and some for pre-training for their main trail races in their countries".
Bhattachan, 58, was early to spot Nepal's potential as a running destination and breeding ground for elite runners. He helped to establish Nepal's first 100-kilometre high altitude ultramarathon in 1995, the Annapurna 100. As the proposed route took a strong hiker four days to walk, the run was deemed impossible and attracted only 25 daring Nepali runners, he says.
"The first runner finished in a mind-boggling time of 11 hours 51 minutes," says Bhattachan. "Nobody could believe it."
In its sixth edition in 2012, the Annapurna 100 (which now offers 50, 75 and 100-kilometre distance options) attracted 100 foreign runners from 26 countries, and 75 Nepali runners.
For accomplished British trail runner Rob James, competing in the Annapurna 100 last year was an enjoyable opportunity to get back to basics. "It was an uncomplicated trail race in an amazing country. No expensive entry fee, no large brand as a sponsor, no hi-tech gear prizes; just a group of runners organising a running race for anyone wanting to run in one of the world's very special places," says James, 47.
But the running destination presents its own risks.
"When things go wrong, they go terribly wrong," says Michael Maddess, event director of Hong Kong-based Action Asia Events, who has organised a three-day running event in Nepal since 2011.
"In 2011, only four days before the event, one section of the course was wiped out due to the worst landslides in years, forcing us to completely reroute the course at the last minute."
During last year's event, keeping competitors on the correct trail was made difficult by curious local villagers taking the ribbons and signs that marked the course.
Samantha Fanshawe, vice-president and event organiser of Hong Kong-based Racing The Planet, which held a roving race in Nepal in 2011, also says the country is a challenging racing destination.
"Logistics were very complicated," says Fanshawe. "We got many confused looks from locals when we started asking for specifics like 'When was this bridge built?' and 'What is the load capacity?'"
Despite the possible hiccups runners may face along the way, the beauty and diversity of the country, as well as the opportunity to test one's limits, continues to attract runners each year, says Richard Bull, local race organiser and founder of the Trail Running Nepal website trailrunningnepal.org 
Apart from races, self-guided running tours in the country are easy to organise, says Bull. "Nepal's established network of trekking tea houses, that provide bed and board, means you can run for days, even weeks, carrying very little."
The joy of the Nepalese trails can also be had not far from Kathmandu, only a four-hour flight from Hong Kong, says British expatriate and former Hong Kong resident Thomas Bellamy.
"Once you're over the first big hills on the edge of the valley you wouldn't know that Kathmandu was just a few kilometres away," says Bellamy, 25. "There are some fantastic climbs all around the valley: Shivapuri National Park, Nagarjun and Chobhar, to name just a few."
The races also give a unique insight into the Nepalis, who are naturally powerful and impressive runners after years of trekking through rural mountain areas. Their talent has been felt in Hong Kong, as Aite Tamang, Bed Sunuwar and Sudip Kulung finished second, third and eighth respectively at the Vibram Hong Kong 100 ultramarathon. Together with Bhim Bahadur Gurung, the runners were sixth in the Oxfam Trailwalker in November, while Ram Khatri and Samir Tamang were on the team that came second.
Aite Tamang, a soldier, believes it is the hardy Nepalese life among challenging and beautiful terrain that makes them great runners. "It makes us want to go out and do our best, for Nepal and for the opportunity of a lifetime," he says.
"If we are good runners, we may travel overseas," adds Sunuwar.
Steve Brammar, HK100 race director, says the Nepalis' performance is just a start. Big things are expected of them this year.
Beyond the country's impressive landscape and the natural running ability of its people, it is the beauty of the Nepalis that Maddess believes makes the journey worthwhile.
"Nepalis always seem to have smiles on their faces no matter how poor they are," he says. "It's very different from the materialistic society ... in Hong Kong."
Bull adds: "You'll meet many different ethnic groups as you traverse the mountains, from Gurungs to Sherpas to Tibetans, and very different ways of living. It gives a different perspective on life."
It is these unique elements that make Nepal the best place in the world for trail running, says Bhattachan. The ex-Gurkha, who also organises the Everest Ultra and manages the top runners, is on a mission to show the world just how good running - and runners - in Nepal can get.
And he has no plans to stop any time soon. "I've run more than 45,000 kilometres in the past 40 years," he says. "I like running adventures in order to keep physically fit and I wish to live more than 100 years."
Nepal race calendar for 2013
March 9: Annapurna 100 Ultra Trail - 50km/70km/100km, annapurna100.com 
March 12: Kanchenjunga Ultramarathon - 49km, himalayanguides.com 
March 29: Trail of the Three Valleys - 353km, trailrunningnepal.org 
March 30: Everest Ultra - 65km, everestultra.com 
April 19: Annapurna Mandala Trail by Raidlight - 250km, leschevaliersduvent.fr
April 27: Mustang Trail Race - 277km, mustangtrailrace.com 
May 29: Everest Marathon - 42km, everestmarathon.com 
October 6: Himal Race - 900km, leschevaliersduvent.fr
October 18: Everest Sky Race - 360km, leschevaliersduvent.fr
November 9: Manaslu Mountain Trail Race - 212km, manaslutrailrace.org