The (Northern) Sporades are an archipelago along the east coast of 
Alonissos Island
Alonissos, Alonisos or Alonnisos Island Aegean Sea and have been declared a marine park because they are a breeding ground for the rare species of monk seal, the Monachus Monachus.
Skiathos Island
Skiathos s the westernmost island in the Northern Sporades group of islands. The Greek island of Skiathos Greek Islands
Skopelos s the largest of several islands which comprise the Northern Sporades island group. It is a beautiful Greek island which attracts thousands of tourists every year. The Greek Island is known for its beautiful beaches with their clean crystalline waters, surrounded by pine trees forests and also for the nice capital, built amphitheatrically in the heart of a bay, composed of white houses with tiled roofs.
Peristera Island
Peristera, also Aspro, locally Xero (meaning dry) is a Greek island in the Sporades
It is administratively part of the municipality of Alonissos and is also directly east of the island of Alonissos
Skyros Island
Skyros the island was known as The Island of the Magnetes where the Magnetes used to live and later Pelasgia and Dolopia and later Skyros . It is known for its lush green landscape, its trekking paths among pine forests and its isolate beautiful beaches. The villages of Skyros are lovely and there are plenty of sites to see on the island.
Source:Wikipedia