Moderator, Iberia Airlines, Airport Lounges, and Ambassador, British Airways Executive Club
Join Date: Feb 2010
Programs: BA Lifetime Gold; Flying Blue Life Platinum; LH Sen.; Hilton Diamond; Kemal Kebabs Prized Customer
Posts: 63,830
Beijing is indeed the best way, and I've done LHR-PEK-ULN, with an overnight stay. It is cheaper but incredibly slow to take a long distance coach from Beijing, or the train (30 hours), not that I've done either. Ulan Bator is pretty fascinating, if a little cold in the winter. You need some patience when dealing with transport there, they check passports and paperwork every hour, on the hour.