Nepal has some of the best trekking in the world, to and around several of the worlds highest mountains, including Mount Everest. Many people visit the country just to trek and the tourism industry is well prepared to facilitate all manner of trekking styles and destinations. On the one hand, you could spend a year planning an expedition to wild and lofty places; on the other, you could land in Kathmandu with no plans and be on the trail to Everest Base Camp in a matter of days.
Round Annapurna trekking is one of the best trekking route in the world at this time. Like Mustang, Dolpo and others hidden valley are sacred place to do best trekking in Nepal.
The Great Himalaya Trail is the Government of Nepals latest tourism product and spans Nepal connecting all of the main trekking areas (mentioned below) with less visited areas in approximately 1,700 km of trails. There is also a lower or cultural route crossing the pahard or mid-hills of Nepal.
Main teahouse trek regions, in each of these areas there are a number of trail options, there is plenty of scope for short treks of less than a week to much longer if you have time and wanderlust.