City of Heraclea, like any ancient city was protected with city walls and towers from various barbaric attacks.
In the western sector of today Heraclea, fully is revealed the great Byzantine three nave basilica, the narthex and porch, as the annexes to the south and north side. The floors of the church and the other rooms are covered with mosaic, which derive various geometric and other figures from the flora and fauna. Mosaics, discovered on the floor of the narthex of the Great Basilica (1963 and 1964) are distinguished by their artistic qualities and iconographic peculiarities. In iconographic terms these mosaic decorations have cosmic significance in accordance with the idea that the church is a microcosm, or Christian universe, in an unusual variant.