Route notes
Why this routing works
This routing uses Washington DC as the domestic gateway on both the outbound and return, linking Atlanta to the long-haul segments in a straightforward out-and-back sequence: Atlanta–Washington DC–Istanbul–Kathmandu, then back via Washington DC to Atlanta. Repeating the same U.S. connection point on both ends can simplify the overall structure of the ticket and keep the itinerary easy to follow.
With only two international stop points beyond the U.S., this is a clean multi-stop setup for a three-week trip. Istanbul sits between Washington DC and Kathmandu in the flown order, which breaks up the journey into logical stages rather than pushing directly from the U.S. gateway to the final South Asia stop.
In economy, the sold range of USD 1,910 to 2,914 places this as a moderate-complexity multi-stop rather than a large round-the-world circuit. November departure timing fits the stated Oct-Dec season window, and the three-week length suggests relatively limited ground time spread across the two overseas stops, so connection pacing and stop order matter more than adding extra cities.
Ticketing-wise, this is best understood as a single multi-stop itinerary with an open sequencing focus rather than separate one-way flights. Keeping the route closed back to Atlanta via Washington DC helps preserve a simple return structure and avoids the added complexity of ending in a different U.S. city.