Trekking into Central Nepal
Located some 30 kilometers directly north of the Kathmandu valley, close to the boundary with Tibet, extending in an east-west direction and bordered on the north by the main peak of the Himalaya, is dominated by Langtang Lirung (7245 meters), the highest in the area. These areas between the Himalayan foothills and the Tibetan frontier, are several regions popular with trekkers. These include Langtang valley, Gosainkunda, Tamang Heritage, Helambu and the high country above Gatlang.
Featured Trips of Trekking into Central Nepal:

Itenerary
Day 1: Kathmandu to Dhunche via Trishuli Bazaar, Day 2: Dhunche to Syabru, DAY 3: Syabru to Lama Hotel, Day 4: Lama Hotel to Langtang Village, Day 5: Langtang Village to Kyanjin Gompa, Day 6-7: Langtang Valley

Itenerary
Day 1: Dunche to Sing Gompa, Day 2: Sing Gompa to Gosainkunda, DAY 3: Gosainkunda to Ghopte, Day 4: Ghopte to Tharepati, Day 5: Tharepati to Khutumsang, Day 6: Khutumsang to Chisopani, Day 7: Chisopani to Kathmandu 
Itenerary
Day 1: Kathmandu to Syabrubesi, Day 2: Trek to Syabrubesi to Gatlang, Day 3: Gatlang to Tatopani, Day 4: Tatopani to Nagthali, Day 5: Thuman to Rasuwagadi, Day 6: Rasuwagadi to Briddim, Day 7: Briddim to Syabrubesi, Day 8: Syabrubesi to Kathmandu 
Itenerary
(From Footprint Book)Day 1: Kathmandu to Dhunche, Day 2: Dhunche to Syabru, Day 3: Syabru to Sing Gompa, Day 4: Sing Gompa to Gosainkund, Day 5: Gosainkund to Ghopte, Day 6: Day to Tharepati and Tarke Ghayang, Day 7: Tarke Ghayang to Kiul, Day 8: Kiul to Pati Bhanjyang, Day 9: Pati Bhanjyang to Sundarijal and Kathmandu
(From Lonely Planet)
Day 1: Sundarijal to Chisopani, Day 2: Chisopanit o Golpu Bhanjyang, Day 3: Golpu Bhanjyang to Tharepati, Day 4: Tharepati to Melamchi Ghyang, Day 5: Melamchi Ghyang to Tarke Ghyang, Day 6: Tarke Ghyang to Kiul – Kul to Kathmandu

Itenerary
(From Alpine trekking company)Day 1: Kathmandu to Trishuli, Day 2: Dhunche to Shyabru, Day 3: Shyabru to Goljung, Day 4: Goljung to Parbati Kunda, Day 5: Parbati Kunda to Gatlang, Day 6: Gatlang to Choten Trail, Day 7: Choten Trail to Tatopani, Day 8: Tatopani to Nag Thali, Day 9: Nag Thali to Timure, Day 10: Timure to Rasuwa Gadi, Day 11: Rasuwa Gadi to Thuman, Day 12: Thuman to Bridim, Day 13: Bridim to Syabrubesi, Day 14: Syabrubesi to Kathmandu
(From Himalayan Idol website)
Day 1: Kathmandu to Syabru, Day 2: Syabru Besi to Gatlang, Day 3: Gatlang to Tatopani, Day 4: Tatopani to Thuman, Day 5: Thuman to Briddim Village, Day 6: Briddim to Lama Hotel, Day 7: Lama Hotel to Langtang valley, Day 8: Langtang Valley to Kanjing Gompa, Day 9: Kanjin rest Day, Day 10:Kanjin Gompa to Lama Hotel, Day 11: Lama Hotel to Thuolosyabru, Day 12: Thulosyabru to Dhunche, Day 13: Drive back to Kathmandu
