The Castle of Potamia, also known as the Upper Castle, holds a significant place in the history of Naxos. This formidable fortress has stood the test of time, with origins dating back to antiquity. However, it underwent reconstruction during the 13th and 14th centuries under the Venetian rule of Marco Sanoudo, who was the island's ruler and also responsible for the construction of the castle in Naxos.

The name "Upper Castle" was bestowed upon it to differentiate it from the Chora Castle, and it offers breathtaking views of the surrounding sea. Notably, the castle featured two layers of fortifications, strategically designed to safeguard the island against pirate incursions. These defensive structures served as a testament to the importance of protecting Naxos and its inhabitants.