You won't miss the gates of the castle. The south gate is called the Paraporti (side gate), but it's more interesting to enter through the northern gate, or Trani (strong), via Apollonos street. Note the vertical incision in the gate's marble column—it is the Venetian yard against which drapers measured the bolts of cloth they brought to the noblewomen. Step through the Trani into the citadel and enter another age, where sedate Venetian houses still stand around silent courtyards, their exteriors emblazoned with coats of arms and bedecked with flowers. Half are still owned by the original families; romantic Greeks and foreigners have bought up the rest.
The entire citadel was built in 1207 by Marco Sanudo, a Venetian who, three years after the fall of Constantinople, landed on Naxos as part of the Fourth Crusade. When in 1210 Venice refused to grant him independent status, Sanudo switched allegiance to the Latin emperor in Constantinople, becoming duke of the archipelago.
Under the Byzantines, "archipelago" had meant "chief sea," but after Sanudo and his successors, it came to mean "group of islands," that is, the Cyclades. For three centuries Naxos was held by Venetian families, who resisted pirate attacks, introduced Roman Catholicism, and later rebuilt the castle in its present form. In 1564 Naxos came under Turkish rule but, even then, the Venetians still ran the island, while the Turks only collected taxes. The rust-color Glezos tower was home to the last dukes; it displays the coat of arms: a pen and sword crossed under a crown.