Kos Castle | Kos

Information

Landmark: Kos Castle
City: Kos
Country: Greece
Continent: Europe

Kos Castle, Kos, Greece, Europe

Nerantzia Castle (Castle of the Knights) is a 14th-century coastal fortification located at the entrance of the harbor in Kos Town. It was built by the Knights of Saint John to control the strategic sea passage between Kos and the Anatolian coast.

Visual Characteristics

The fortress consists of two concentric walled enclosures. The outer wall features massive circular bastions and artillery ports, while the inner wall is reinforced with rectangular towers. The masonry incorporates ancient marble fragments, columns, and inscriptions scavenged from the ruins of the nearby ancient city and the Asklepion. A stone bridge across a former moat (now Finikon Avenue) connects the castle to the town.

Location & Access Logistics

The castle is situated on the eastern side of the Kos Harbor (Mandraki). Entrance is via the bridge located next to the Platanos of Hippocrates. It is a 5-minute walk from the central bus terminal and the ferry port. Vehicle access is prohibited within the castle; parking is available at the public lots near the harbor or behind the municipal building.

Historical Origin

Constructed in phases between 1380 and 1514, the castle was a primary defense against Ottoman expansion. It was named "Nerantzia" after the numerous bitter orange trees (nerantzies) planted in the area. Following the Ottoman conquest in 1522, it served as a garrison and prison. It suffered damage during an earthquake in 1933 and was subsequently restored by Italian archaeologists.

Key Highlights & Activities

Visitors can walk the perimeter of the ramparts, which offer views of the harbor and the Turkish coast. The central courtyard contains an open-air museum displaying ancient altars, sarcophagi, and architectural members embedded in the walls. The "Governor’s Palace" remains and the coat of arms of the Grand Masters of the Knights are notable features.

Infrastructure & Amenities

The site is managed by the Ministry of Culture and requires an entrance fee. Basic public restrooms are available near the ticket office. There are no food or beverage vendors inside the ruins. 5G and 4G signals are strong throughout the site. The terrain is uneven with loose gravel and steep stone steps, making it largely inaccessible for mobility-impaired visitors. Natural shade is minimal.

Best Time to Visit

The castle typically operates on restricted morning hours (08:30–15:00) and is closed on Tuesdays. It is best to visit immediately at opening to avoid the heat and peak crowds from cruise ships. For photography, the morning light provides the best illumination for the harbor-facing walls.

Facts & Legends

A local historical detail is the presence of the "Tree of Hippocrates" bridge; the moat that once separated the castle from the island was filled in the 19th century, transforming the castle from an island fortress into a peninsula. Legend holds that the Knights used secret underground tunnels to move supplies and troops between the castle and other defensive points in the town center.