Manaslu Circuit trek It's one of the beautiful Himalayan treks. The length of the trek is about 170 km. The highest point is Larkya La (Larke Pass) at an altitude of 5106 meters. Pathway alternately rising and falling. Total elevation is due to this profile about 9,000 meters. During the route you will go trough all the vegetation zones from tropical to alpine.
Itinerary
Start of trek in Soti Khola (700) - to transport from Kathmandu you may use the bus or jeep
1. Machha Khola (869) - 7 hrs to go
2. Tatopani, Jagat (1340) - 7.5 hrs
3. Eklebhatti, Dyang (1860) - 7.5 hrs
4. Ghap, Namrung (2630) - 7.5 hrs
5. Lho (3180) - 4 hrs
6. Samagaon (3520) - 3.5 hrs
7. Acclimatization day - trip to Manaslu Base Camp
8. Samdo - 4 hrs
9. Dharmasala (4460) - 3.5 hrs
10. Larkya La (5106), Bimthang (3590) - 11 hrs
11. Goa,Tilije, Dharapani (1960) - 8 hrs
12. Tal, Chyamche (1430) - 3 hrs
13. Syamge (1100) - 2 hrs - continue by jeep to Besi Sahar (760)
To find the cache you must complete about 6 days trekking route Manaslu Circuit trek to the village Samagaon. From there you can follow the side road to the lake Birendra Tal. Birendra Tal is named after name of late King Birendra of Nepal, is a turquoise lake at the foot of the Manaslu glacier. It can be reached by 45 minutes walk from Samagaon. The lake can be visited on the way from Samagaon to Samdo too, as it is a relatively short diversion from the main trail.
The cache is hidden near the shore of this glacial lake. Cache is under the biggest stone. For find use these fotohints.

View the cache place from the way to Manaslu Base Camp

The biggest stone

Here