The Palace of the Grand Master of the Knights of Rhodes (Greek: Παλάτι του Μεγάλου Μαγίστρου), also known as the Kastello (Greek: Καστέλο), is a medieval castle in the city of Rhodes, on the island of Rhodes in Greece. It is one of the few examples of Gothic architecture in Greece. The site was previously a citadel of the Knights Hospitaller that functioned as a palace, headquarters and fortress.