Dhaulagiri, the 7th-highest mountain in the world, was thought to be the highest after it was discovered in 1808, replacing the previous record holder, Chimborazo in Ecuador. It held this distinction for nearly 30 years, until Kangchenjunga was discovered and assessed to be 400 metres higher. Its name is derived from the Sanskrit "Dhavali giri", or White Mountain. Located in Nepal, in the Dhaulagiri Himal, which is a sub-range of the Himalayas, it is usually accessed via the small local town of Beni, which in turn can be reached by bus from both Pokhara and Kathmandu.
Dhaulagiri certainly looks ridiculously high, its main triangular peak towering above the huge massif of which it is the centre - a massif that contains 5 peaks of 7600 metres or higher, and 15 of more than 7000 metres. Like the Annapurna massif, it rises over 7000m in vertical distance in roughly 30km of horizontal distance over the Kali Gandaki gorge. This location is unique in the world, with two 8000-metre peaks facing each other over a deep river valley. In terms of prominence, or the independence of a mountain over its surrounding terrain, Dhaulagiri has few rivals. Its south and west faces each have drops of over 4000 metres to their base.
The first attempt to scale Dhaulagiri came in 1950, when a French expedition did reconnaissance with the intention of being the first climbers in the world to summit an 8000-metre peak. Apparently this trip was supplied with a large amount of public funding, in an attempt by the French government to rebuild national pride after the humiliations of the Second World War. They climbed to 5200m, when they assessed the southeast ridge and the south face that they would have to climb to reach it, and decided the task was impossible. Their story had a happy ending, though; they continued on to Annapurna, only a short distance away across the Kali Gandaki, and made history.
Several failed expeditions were made over the following years - these mostly attempted the northwest ridge, known as the "pear route" due to its shape. However, on the last of these in 1958, one of the members, Max Eiselin, became convinced that the best way up the mountain was via the northeast ridge. Unfortunately for him, he couldn't get a climbing permit in time to try the route himself, and an Austrian team made the first attempt on the northeast spur the next year, in 1959. They reached 7800 metres; however, one of their members fell into a crevasse and died, and an avalanche destroyed one of their camps; with their morale destroyed and their safety threatened they decided to turn back.
This left Eiselin free to try his route, and in 1960 he and Kurt Diemberger, Peter Diener, Ernst Forrer, Albin Schelbert, Nyima Dorji and Nawang Dorji made the first successful ascent. It didn't go without hitches; they approached by air, and their aircraft crashed on the way. No one was killed, but they had to abandon the plane on the mountain and go down again on foot. Their route via the northeast spur has since become the standard ascent route. Incidentally, they set a world record that persists today, for the highest landing of a fixed-wing aircraft (5700 metres).
Dhaulagiri was not actually climbed again until 1970. Since the early days, it has been summited by every conceivable route, but many of these climbs are exceptionally difficult, and there have been many deaths of accomplished and experienced climbers. It has a reputation as one of the more dangerous of the 8000ers, with a fatality rate of 18% (313 successful ascents, 56 deaths). Like all of the big mountains, recent years have seen the death rate decline dramatically; however, the number of ascents has not risen sharply as it has for, for example, Everest and Cho Oyu, suggesting that it is still a target for experienced climbers only. Its difficulty is for the same reasons as that of Annapurna - the weather conditions and topography lead to a higher-than-normal risk of avalanches, and of the break-off of seracs (ice cliffs).
In addition to the mountain itself, the Dhaulagiri area is, like Annapurna, home to some of the world's most beautiful and demanding trekking country. Whereas the Annapurna circuit is quite tourist-friendly and well-travelled, the Dhaulagiri trek was opened more recently and is much more physically demanding, involving glacier walking, intense cold, and all the attendant difficulties of exertion at high altitude. Most of the Annapurna circuit passes through inhabited areas with facilities, whereas much of the Dhaulagiri trail goes through pristine wilderness and over dangerous climbs and precipitous drops. Good weather should make it navigable for people in good health who have acclimatized well; bad weather or poor health will make it extremely dangerous.
Trekking around Dhaulagiri: http://projecthimalaya.com/news-96-around-dhaulagiri.html
More Trekking: http://www.nepalmakalu.com/dhaulagiri1.htm