1. Milos: Known for its stunning rock formations, secluded beaches, and charming fishing villages.
2. Naxos: Boasts beautiful sandy beaches, ancient ruins, and a vibrant local culture.
3. Serifos: A peaceful and unspoiled island with picturesque villages and breathtaking landscapes.
4. Syros: Combines historical charm with a vibrant cultural scene, featuring neoclassical architecture and a lively waterfront.
5. Amorgos: Offers a tranquil atmosphere, rugged cliffs, and the famous Monastery of Panagia Hozoviotissa.
6. Ikaria: Known for its laid-back lifestyle, hot springs, and the longevity of its residents.
7. Lefkada: Offers stunning beaches, turquoise waters, and is accessible by a causeway, making it feel like an island.
8. Samothrace: A nature lover's paradise with majestic waterfalls, hiking trails, and ancient archaeological sites.
9. Folegandros: A peaceful island with dramatic cliffs, charming villages, and panoramic views of the Aegean Sea.
10. Astypalaia: A hidden gem with traditional white-washed houses, tranquil beaches, and a medieval castle.
These underrated Greek islands offer unique experiences, natural beauty, and a sense of authenticity that is often less crowded and more off the beaten path compared to popular tourist destinations in Greece.