Travelling in confidence with Olympic Holidays in 2020. Updates on travel requirements available here

Built in the 14th century and used by the Knights of St John, of the Castle of the Knights was a defence against the troops of the Ottoman Empire. Today the fortifications are a popular attraction for visitors, not least because the ramparts offer fantastic views over Kos Town.

The commanding walls, gun ports and robust, rounded towers at each corner contrast with much of the crumbling interior and visitors with young children are Olympic Holidays advises to take care around steep staircases and high unfenced walkways.

The fortress stands at the entrance to Kos Harbour, almost opposite Bodrum Castle on the Turkish coast across the sea, and is divided into two areas, accessed by a bridge across a moat which was filled in during the early 20th century.

Its alternative name, Neratzia, roughly translates as ‘sour oranges’, a reference to trees renowned for bitter fruit which used to grow nearby.

There is a frieze of masks and garlands above the main gate but it is thought that this, like more of the inscriptions and heraldic reliefs at the castle, had been removed from somewhere else. Let Olympic Holidays know what you think!

Much of the material used for building was taken from other ancient sites on the island, including the Agora and the Asklepeion sanatorium where Hippocrates, the so-called Father of Medicine, once worked.

A collection of artefacts, including altars, is held in a museum which is housed on a former warehouse site on the northern side of the castle between the two precincts.

The castle finally fell to the Turkish invasion in 1523, having been damaged by an earthquake just before the turn of the century but the Ottomans restored much of the site and adopted it as a barracks for themselves.

Worse damage was done by a gunpowder explosion in 1816 and more restoration was undertaken by the Italian Archaeological Department.