The huge marble gate which towers over the islet of Palatia on the left side of the port of Naxos, is the trademark of the island, but also a unique monument of the entire Aegean.
The famous and enigmatic "door" that rises above the rock was once the gateway of a large temple, probably dedicated to the god Apollo. It consists of four pieces of local marble, weighing about 20 tonnes. Portara, as the locals refer to it and have been for some time, due to its large size (nearly 6 meters height and width of more than 3.5 m), was built around 530 BC by the tyrant Lygdamis in accordance with the specifications of the temple of Olympian Zeus in Athens and was never completed. The entrance was in the west, which was unusual for such a temple at that time. Later, in the early years of Christianity, the temple was converted into a church and the Venetians used various parts of it to build the castle of Naxos.
Since 1919, the small island has been connected to the mainland via a paved pathway. Nowadays, visitors can admire this special monument at any time of the day (there is no entrance).