Now in the centre of Sofia, in late Antiquity the basilica of St Sophia (the name means Holy Wisdom) was outside the then city walls. Initially it was a humble cemetery church or, more accurately, a sequence of three churches built one after – and on top of – the other in the span of two centuries. A fourth church, the one you see today, was built in the late 5th and the early 6th centuries.

The church remained in use throughout the Middle Ages. In the 16th Century it was turned into a mosque and was abandoned in the 19th Century after a series of earthquakes left it badly damaged. At the end of the century it was used as a storage room and as a watchtower for the local fire brigade. It was only after 1911 that the basilica was surveyed and restored. St Sophia became a functioning church in 1998. 

After centuries in which ecclesiastical life did not exist, today St Sophia's interior is whitewashed. The size of the church – about 46 m in length and 20 m in width, and a cupola some 20 m in height – makes it an imposing sight. Its architecture is also intriguing, as it presents a rare combination of a cross-shaped three-nave basilica and a cupola. The subterranean level is opened to visitors, presenting a dark labyrinth of sarcophagi and painted tombs from the necropolis which the church once served. 

The St Sophia is at once a functioning temple and a museum, a dual existence which is unlike those of many other basilicas across the country which only serve scientific purposes and welcome tourists.