"Barbican (a term derived from the medieval Latin barbecana – the outer fortification of a city or fortress) is an element of late medieval fortifications designed to guard the approaches to the city gates. It consisted of tower or bastion-type fortifications around the outer gate connected to the inner city gate by a covered passage called the neck. Inside it had a system of covered galleries guarded by neighbourhood guards and city defenders during the attacks.
The tower was designed by the Ruthenian architect of the late 16th – early 17th century Jakub Madeline who was master of the Lviv masonry shop. He was Graubunden by origin and is considered to be the author of the church in Stryi (1599), the Church of St. John the Baptist in Izyaslav (1599-1630), the church of St. Michael and Bernardine monastery in Izyaslav (1602-1630), Lutsk Gate in Dubno (1623), the Tatar Gate and the Great Synagogue in Ostroh. He also participated in the design of the bath of the Assumption Church in Lviv (1628)."
Nowadays the colourful ruins look new, as the lost fragments of the tower have been restored thanks to modern technologies. There is an art space "Cultural Barbican", which functions as a venue for art events in the city of Ostroh.