The National Marine Park of Alonissos Northern Sporades was the first marine park established in Greece and is currently the largest marine protected area in Europe (2.265km²). Besides the sea area, the Park includes the island of Alonissos, six smaller islands (Peristera, Kyra Panagia, Psathoura, Piperi, Skantzoura and Gioura), as well as 22 uninhabited islets and rocky outcrops.

After a period of internal and external migration, the population of Alonissos has been showing a small but steady rise over the last decades, but not exceeding 2,000 permanent residents. The main occupations of the inhabitants are agriculture farming, livestock farming and fishing, while tourism has been booming in recent years. The establishment of N.M.P.A.N.S. is expected to play an important role in the sustainable development of the region, offering new job opportunities while supporting the local traditional professions.

The area shows a great scientific and cultural interest. In the wider area of the Park there are findings dating back to the Prehistoric era, the Classical period and Byzantine Empire (shipwrecks, old monasteries and churches).

In the areas where public access is permitted, visitors can engage in swimming, diving, wildlife watching, taking pictures, recording video, visiting cultural monuments, hiking etc.

There are specific restrictions on sport fishing. Hunting is allowed only on the island of Gioura, subject to a special permission.