On the site of today’s Evksinograd residence, about 6 km north of Varna, a port settlement existed on the small cape of St. Yani from the 4th to 6th centuries. During the Middle Ages, it developed into a town with active trade and navigation, appearing on nautical charts from the 14th to 18th centuries. By the late Middle Ages, only the port and a small guard fortification remained.
Known under various names on historical maps—such as Castritsa, Katrizzi, Katrichi, Ketritsi, Castrizzi, and Katria—all derived from the Greek castro (fortress), the site was first surveyed in 1899 by Karel Škorpil. More detailed excavations were conducted from 2004 to 2011 under Professor Dr. Valentin Pletnyov, revealing the medieval fortified town’s structure.
A large portion of the northern, land-facing fortress wall has been preserved, over 200 meters long, 1.8–2 meters thick, and up to 3 meters high. Five circular bastion towers were situated along the wall, and at the eastern end, a rectangular tower was later supplemented with a triangular Ottoman bastion. A second, thinner wall running perpendicular to the main wall suggests a citadel, further reinforced by towers, indicating Ottoman use in the 15th–16th centuries.
In the western corner, an inner round tower was replaced by a four-walled keep, later reinforced with an outer stone casing atop a rammed-earth embankment. This casing, likely from the 15th century, was intended to withstand artillery, while the keep itself predates the Ottomans, evidenced by fresco fragments indicating a chapel.
Excavations reveal a clear street network, pavements of stone slabs and cobblestones, a small single-nave church with adjacent monastic buildings, and four elongated inns arranged around a small square linking the port to a secondary city gate. Other foundations belong to residential structures.
The church evolved from a parish church with a cemetery, probably for sailors and travelers, into a monastery. Built of quarried stone with mud mortar, it had a wooden roof covered with thin aspid slabs. Other buildings used timber framing with clay-wattle walls and wooden roofs, a construction method known in Bulgarian lands from the 17th–19th centuries.
Coin finds dated to 1404 suggest the city was gradually abandoned afterward, though the port and likely the citadel watchtower remained in use until the 16th century. The additional triangular bastion, as at Kaliakra, supports its role as a port watchtower. Today, the remains of the fortress of Kastritsi are preserved in the park surrounding palace "Evksinograd“.
