Often referred to as if it were a single mountain, Annapurna is actually a 55km long massif, containing 6 peaks higher than 7,200 metres: Annapurna I (8,091 m), Annapurna II (7,937 m), Annapurna III (7,555 m), Annapurna IV (7,525 m), Gangapurna (7,455 m) and Annapurna South (7,219 m). Its highest point, Annapurna I, is the 10th-highest mountain in the world. It is part of the Himalayas, on the eastern side of the Kali Gandaki river gorge, across from the Dhaulagiri massif. The whole surrounding area is preserved as the Annapurna Conservation Area Project, and includes several beautiful and popular treks.
The name Annapurna comes from Sanskrit, and is often translated as Goddess of the Harvests or The Provider but in fact literally means "full of food" and therefore presumably could be translated as The Devourer, a name that might be more appropriate considering its fearsome reputation. In Hinduism, the goddess Annapurna is an avatar of Durga associated with fertility and agriculture.
Annapurna I was the first 8000-metre mountain to be climbed, by Maurice Herzog and Louis Lachenal on June 3, 1950 - a somewhat surprising fact considering that all the peaks in this massif are considered to be among the world's most dangerous to climb. They climbed it using a crude map and on an unplanned route, a foolhardy adventure that almost cost them their lives; having made it to the summit, their descent turned into a nightmare, with frostbite costing Herzog all his toes and fingers, and Lachenal all his toes. Their ordeal was captured in an account by Herzog, simply titled "Annapurna", which was at one point the bestselling mountaineering book ever written. Annapurna I was not successfully scaled again until 1970.
In fact, although I have written up K2 with the tagline "The world's deadliest mountain" because of its popular reputation, there is just as strong an argument in favour of Annapurna, which has a fatality rate of 41%, the highest in the world. This doesn't mean that 41% of all climbers die - the convention is to compare the number of successful ascents to the summit against the total number of deaths. In Annapurna's case, there have been 130 successful ascents against 53 deaths; Everest, for example, has a fatality rate of only 9%. Even if you take account only of modern (post-1990) statistics, in which there is a greater general level of climbing knowledge, safety procedures and technology, Annapurna's fatality rate of 20% still dwarfs the 4.4% of Everest. The reason for this peak's danger is its particular weather conditions and topography, which lead to a high risk of avalanches and of large seracs (ice cliffs) which are continually in a process of breaking off and reforming. In his book Annapurna: 50 years of expeditions in the Death Zone, Reinhold Messner discusses the climbing conditions in detail, and shares his thoughts on constructing a successful and safe ascent plan, which centre around avoiding routes likely to be exposed to falling snow and ice.
There are 3 major treks in the Annapurna Conservation Area - the Jomson Trek which leads through Jomson and Muktinath, the Annapurna Sanctuary route which leads to the Annapurna base camp, and the famous Annapurna Circuit, probably the most popular, which leads in a circle around the entire Annapurna massif, and takes in the Jomson Trek on the way. Trekkers usually start in the nearby town of Pokhara, and the area is so outstanding that two thirds of all trekkers who visit Nepal go walking in this region - it is accessible, incredibly beautiful, and highly diverse in scenery, as well as being fully inhabited. Travelling to Annapurna has been somewhat problematic recently due to the political unrest in Nepal. Apparently it was still relatively safe for tourists, as neither side (the government of the ruling Nepalese royal family and the Maoist rebels) was interested in killing foreigners, but apparently it was common for the Maoists to demand "contributions" from trekkers they encountered, in order to avoid "accidents" from befalling them. This has probably all blown over with the very recent resolution of the political situation.
Another noder, Matthew, says re Annapurna: Interesting personal anecdote about Annapurna and the Maoist rebels- When I went with my adopted sister, we got stopped by the rebels, who demanded a "contribution". Advised to simply pay a couple hundred rupees by another trekker so as to avoid conflict, we did so, and received a receipt, kindly signed and dated by the insurgents. No kidding.
Annapurna: 50 Years In The Death Zone