By air
We travelled to Bulgaria twice. Both times we flew low-cost airline WizzAir from Budapest to Sofia. In 2007 WizzAir discontinued the Budapest-Sofia flight (at the moment they fly on London (Luton)-Sofia, Rome-Sofia and Dortmund-Sofia routes). From Budapest they still fly to Burgas and Varna, at least during summer, as these two places are convenient jumping-off points for Golden Sands and Sunny Beach resorts.
Sofia is also serviced by low-cost airlines Germanwings and easyJet and many conventional airlines such as Lufthansa, Austrian Airlines, Turkish Airlines, British Airways, Alitalia, Air France and naturally Bulgarian carrier Bulgaria Air.
By train
Sofia international train connections include Belgrade, Ljubljana, many other central European cities and Athens. Trains are rather slow – a trip to Ljubljana via Belgrade for instance takes almost 21 hours. We don't know what condition the trains are in as we never tried to travel to Bulgaria by train. Lately we prefer to take faster alternatives (does it mean that we are getting old?). More information about international train connections is avaliable at Bulgarian Railways website.
By bus
There are several international bus lines connecting Sofia with central and western Europe. One convenient (although tedious) bus line connects Sofia with Florence via Ljubljana, Triest and Venice Mestre. There are other bus lines connecting Sofia with Istanbul, Skopje, Athens, Bucharest, Vienna, Budapest and even Madrid. Visit Sofia bus station website for details.