The Annapurna Circuit

The Annapurna Circuit attracts a relatively high number of trekkers in Nepal. As the name itself suggests, this trail goes on a circuitous route around the entire Annapurna massif, visiting the Tibet-like country on the northern slopes of the Himalaya and the dramatic Kali Gandaki gorge. Much of the trek is through lowland country, but there is one high pass, "Thorung La" (5,380m). The trail over the pass is steep but in good shape and not hard to follow. This is the one point of the entire circuit where you really feel you are amidst the mountains. However you should be aware of altitude sickness and be prepared for weather extremes as the Thorung La is notorious for changing its moods. The pass is usually snowbound and un-crossable form mid-December to mid-April.
The Kali Gandaki gorge is another spell binding part of this trip. Known to be the worlds deepest river gorge the trail upto the Jomsom (and Upper Mustang) actually goes side by side with the river giving the lonely trekker company and groups something to talk about. Thus the Annapurna circuit is an extraordinary trek, truly one of the world's best. It requires at least three weeks. But due to the popularity of this route it can sometimes tend to be crowded.