Portara of Apollo
As you arrive by ferry, you will be welcomed by the emblem of the city, the Portara.  The Portara is a 2,500-year-old marble doorway that leads to nowhere. The islet is connected to the mainland via a paved footpath accessible on foot when on the harbor of Naxos.

While many believe that originally the intention was to build a building in the honor of Apollo, the Greek God who protects music and poets, not every agrees some believe it was to honor Dionysus. The Portara faces the island of Delos, the birthplace of Apollo and offers a nice view of the sunset.  Unfortunately, due to war, the construction was stopped. The work did not resume and was never completed. The doorway or gate is the only section standing. 
The Portara is located on a small islet, a short walk from the harbor of Naxos Town.  You can’t miss it.

You will notice that on one side of the water is agitated while on the other there is a beach and people enjoying the water. 

Take the time to look at the town and its different areas. A section of the town square white brushed houses looks like a Minecraft style.

When in this area you can visit the town, access to a beach, the castle, restaurants and hotel options are in proximity.