KOs island is a picturesque Greek island in the Aegean sea, belongs to the Dodecanese (Southern Sporades). Fascinating ancient history and rich cultural and historical heritage of the island annually attract a huge number of travelers from all over the world. One of the main attractions of KOs is considered to be the Castle of knights, located near the Harbor in the homonymous capital of the island.

The knights of St. John settled on the island in the 14th century and in order to protect themselves from unwanted invasion of the Turkish invaders, began building a defensive fortress. Grandiose fortification was built on the ruins of the ancient city. During its construction the knights used local materials, including stone and marble, preserved from ancient buildings. The 16 century the existing realities demanded the construction of additional fortifications, and in 1514 was completed outer defensive walls. Between the inner closure and new fortifications there was a deep ditch filled with water, through which ran a massive stone bridge. The ditch drained long ago and is overgrown with trees and bushes, but the stone bridge is perfectly preserved to our days and through it one can enter the territory of the ancient castle.

Unfortunately, today the once magnificent structures were only majestic ruins, which, however, give quite a colorful presentation about the past power of the knights of St. John. Partially preserved massive battlements, watch towers, loopholes and internal fragments of buildings. On the gates of the fortress and today you can see the coat of arms of Grand master Pierre de Aubusson.

Today the island of KOs is one of the most popular and visited Islands of Greece. Ruins of a medieval Castle knights-knights are not only one of the most visited attractions of the island, but also an important archaeological and historic monument.