Neapolis was likely founded by Thasian settlers in order to manage their gold mines on the mainland. It was a close ally of Athens until it was conquered by Philip II, after which it became a port for Philippi.
Its closeness with Athens is demonstrated by the image of Athena Parthenos on its coins. The gorgon on the obverse has made their coinage highly collectible, though luckily the city was quite rich during that time, likely due to its independence from Thasos and thus control over the mines itself. That allowed them to mint an abundant issue and keep the prices of these interesting coins within reason.
The sanctuary to Athena Parthenos was important in ancient times and parts of it may still be seen today.