Tsum Valley Trek and Manaslu Circuit Trek are two of the most challenging treks in the Himalayas that provide a once-in-a-lifetime experience. If you are an adventure seeker looking for new challenges and less busy trails but still wanting to be close to nature, the Manaslu Circuit and Tsum Valley Trek are for you. The Manaslu region began trekking in 1991, and Tsum Valley welcomed foreign visitors in 2008. The unspoiled vegetation, ancient Buddhist culture, and exotic species have all been well-preserved and maintained in these two territories, which have been closed for decades.