Sofia

Two days split Sofia by side of town: the first around the square and the Alexander Nevsky Cathedral, the second on Vitosha, the mountain that starts where the city stops. A third day, if there is one, goes on a day trip — to Rila Monastery or Plovdiv. Under the centre itself, around Serdika metro station, Roman streets, baths and a basilica came up during digging in 2010–2012, from the years the city was called Serdika; they now sit under a glass roof, free to see.

The city has carried the name Sofia only since the late 14th century, after the Hagia Sofia basilica; before that it was Serdica, then Sredets. A settlement at Slatina, in today's north-eastern part of the city, dates from the 6th millennium BC, which makes Sofia one of the few cities in Europe inhabited without a break for that long.

Sofia airport has its own metro station on line M4, so the ride from the terminal to the centre needs no change and takes about 20–25 min, on an ordinary fare of €0.80 — the cheapest way into town; a taxi at a fixed rate runs €13–14. A city bus runs to Aleko, the trailhead on Vitosha — which is also why the city splits into two days, since town and mountain ask for a different pace. A third day, on a longer trip, goes further: 2 h 30 (one way) to Rila Monastery or 2 h 40 by train to Plovdiv.