Nepal: Helambu to Gosaikund to Langtang in 14 days

A combination of two teahouse treks north of Kathmandu, starting from Helambu-Gosainkund trek and continuing to Langtang valley trek. Most days are 4-5 walking hours, allowing to complete the whole route in about two weeks. Carrying your own small pack is possible by staying and eating in local guest-houses along the way. You'll need to purchase a Langtang National Park permit (about 25 USD) at Tourist Service Center, Bhrikutimandap, Kathmandu, see https://ntb.gov.np/plan-your-trip/before-you-come/park-entry-fees
Season: spring before the monsoon (Mar-May) or autumn after the monsoon (Sep-Nov). Snow is possible any time, more likely during winter (Oct-Apr). Langtang and lower altitudes are walkable any time except summer (Sep-May). Summer monsoon time is not recommended (Jun-Aug).

Day 0: Obtain a Langtang National Park permit in Kathmandu, and take a 4-5 hour Jeep from Kathmandu to Kutumsang (2,500 m). Another approach is by tarmac road to Melamchigaon, then one tough day to join the main trek (this saves one walking day overall).
Days 1-4: Ascend 2,000 m over 4 days to Gosainkund lake (4,400 m).
Days 5-6: Descend 2,500 m over 2 days to Langtang valley (1,800 m).
Days 7-9: Ascend 2,000 m over 3 days to Kyangjin Gompa (3,800 m) along the Langtang valley. 
Day 10: Optional full day loop to climb Tserko Ri at 5,000 m, or just a rest day.
Days 11-13: Descend 1,300 m part of the way back down the Langtang valley to Rimche (2,500 m), and fork north towards a level path along the mountainside to Bridhim (2,200 m).

Trail from Kaṭumsāṅ to Briddhim