The island's capital boasts one of the largest old towns in the Cyclades. The small whitewashed streets are a maze, which shelter its inhabitants from the effects of the, at times, vicious northerly winds. The layout, also had the useful side-effect of confusing and confounding invaders in medieval times.
Many ancient ruins have been found in these small streets and archeological sites abound.
Very much a part of the old town, Parikia's traditional Market street or 'Agora', stretches from the main square just behind the port to the Church and square of Zododcho Pigi, near the end of the seafront road. Here you'll find shops, banks, cafes, restaurants, and numerous art galleries which hold exhibitions all through the summer months. Between the Agora and the 'Paralia' or beach road is the Kastro. Nowadays there is not much than a large wall constructed out of the remains of an ancient temple to Athina but the views from the church of Agios Konstantínos above the Kastro are well worth the visit alone. (Sunsets are pretty amazing from here too!)
The pretty little church of Agios Fokas, which guards the entrance to the bay of Parikia lies at the end of a great walk around one of the largest natural harbours in the Aegean. En route are the beaches of Livadia, Krios, Marcello, a number of small less crowded coves, and some spectacular views.
For sporting enthusiasts there are numerous opportunities. The 'NOP', or sailing club, offers sailing lessons and has a large beach volleyball court, at nearby Pounda (opposite Antiparos), there are dive, wind and kite surfing schools. On the way to Agia Irini there is a tennis club, which provides tuition at all levels and in Parikia a gymnasium with a wide variety of activities ranging from yoga to courses in self defense.
Alternatively, you could just relax over a large cold beer, and drink in the sights and sounds of this pretty, unspoilt Greek town.