These islands are located all around Alonissos, which is the natural habitat of rare flora and fauna species and has great underwater ecosystem. The islands around Alonissos are the core of the National Marine Park of Sporades complex (Zone A).
- Gioura or Giaros (which means “cavernous”): An island with a huge cave, where a rare species of wild goat lives.
- Kira Panagia: The homonym Monastery (12th century), glebe of Megistis Lavras of Athos, where the old oil press and the flour mill are preserved in excellent condition is located here. The island has two large natural coves, Aghios Petros (W) and Planiti (E). The latter is one of the biggest natural ports of the Mediterranean.
- Ksiro or Peristera: Uninhabited island in Zone A, which is situated opposite to Steni Vala, close to the eastern coasts of Alonissos, surrounded by beautiful beaches ideal for peaceful swimming.
- Piperi: This island is the centre of the Marine Park and the passage is forbidden. Ships are forbidden to sail closer than the range of 3 miles to the island.
- Skatzoura: It is popular for Evangelistrias Monastery.
- Psathoura: The only volcanic island of North Sporades complex, where there are still ruins of a destroyed ancient city. Due to ground subsidence in ancient times the island was separated into two smaller islands called Psathoura and Psathouropoula. In the island caves Mediterranean seals live.