Within the city of Veliko Turnovo the fortress of Tsarevets which dominates the skyline presents an impressive sight. Commanding a hilltop overlooking the city and the Yantra River meandering around it, the site dates back to the 4th millennium. The Thracians and the Romans, and after them the Byzantines and later the Bulgarian tsars laid claim to this monumental complex where the wind howls from the valleys beyond and evening time takes on an eerie glow. The site has revealed over 400 houses, 18 churches, the royal complex, the Baldwin Tower, after the crusader, Balwin of Flanders, who sacked Constantinople only to be was imprisoned and later executed here. The patriarchal Church of the Ascension of Christ occupies the summit. The frescoes inside the church are contemporary, larger than life persona and events from medieval history.