Why Sofia for a city break?
Sofia is Europe's most underrated capital and its second-highest (after Madrid) — a city of 1.3 million sitting at 550 metres with the Vitosha mountain rising to 2,290 metres directly behind the city centre, visible from the main boulevard. It is extraordinarily cheap, walkable in its historic centre, and rich in archaeological layers: Roman Serdica underlies the modern city, and walking the pedestrianised centre means stepping over excavated Roman streets visible under glass panels in the pavement. The Alexander Nevsky Cathedral is one of the largest Orthodox churches in the world.
From London and several UK airports it's three hours — direct flights from Heathrow, Gatwick and Manchester with British Airways, Ryanair and Wizz Air. Sofia Airport is 10km from the centre (Metro Line 1, €1, 20 minutes). The city is among the cheapest in Europe: a complete dinner with wine costs under £10, a beer is under £1.50, and a taxi across the city is £3. Go in April to June or September to October; December brings a Christmas market to the Alexander Nevsky Square and snow on Vitosha. January to March is cold but very quiet and very cheap.