Gardiki Castle is a significant historical fortress located in the southern region of Corfu, near the village of Agios Mattheos. This archaeological site represents one of the three major Byzantine-era fortifications on the island, alongside Angelokastro and Kassiopi Castle. The castle's strategic position on a low hill provided control over the southern coastal plains and the Corfu Channel. Historical evidence and architectural analysis date its construction to the 13th century, during the period of the Despotate of Epirus, under the rule of Michael I Komnenos Doukas or his successor, Michael II Komnenos Doukas. The fortress features a unique polygonal layout with eight imposing towers, a design characteristic of late Byzantine military architecture. It served as a crucial defensive outpost, protecting the agricultural hinterland and the vital southern approaches to the island. Throughout its history, Gardiki Castle played a role in the island's defense network, particularly during the period of Angevin rule. Following the Ottoman sieges of Corfu in the 16th century, its military significance gradually declined. Today, it stands as a protected archaeological monument, offering visitors insight into the medieval defensive strategies and the complex history of Corfu under Byzantine and subsequent rulers. The site provides panoramic views of the surrounding landscape, including the Korission Lagoon and the Ionian Sea.