Booking some interesting multi-city flights from London to Nepal and Istanbul at once is possible with Star Alliance member Turkish Airlines. Such a routing is now possible to purchase already for £285! This is a price for round-trip incl. all charges and checked luggage. Flights are also available at the end of November which is one of two main seasons for hiking in Nepal and considered as best time to visit this beautiful country.. To reach the lowest fare you have to book your multi-city ticket with at least two nights in Turkey on your way to Kathmandu..
If interested in this deal with Turkish Airlines look for flights departing from London in September or November 2017. Max stay 4 months. Valid for bookings made till end of May 2017. If interested in this solution you can refer below to our booking sample and few travel dates.
Booking sample
Travel samples
10.9. - 12.9. - 22.9.
17.9. - 19.9. - 2.10.
13.11. - 15.11. - 30.11.
20.11. - 22.11. - 8.12.
23.11. - 25.11. - 11.12.
26.11. - 29.11. - 15.12.
30.11. - 2.12. - 22.12.
Booking sample of cheap Multi-city flights from London to Nepal + Istanbul from £285 here. In this case you would fly from London to Kathmandu on 20th of November. Your return flight from Nepal back to Europe would be on 8th of December 2017.