Kokkinokastro Beach, located about 4 km from Alonissos' harbor, is renowned for its breathtaking landscape of red rocks, green trees, and turquoise waters. The beach offers a mix of sand and pebbles, with clear waters ideal for swimming and snorkeling. It is part of a serene natural environment, perfect for relaxation and exploration. Visitors often praise the friendly staff at the local beach bar, where sunbeds and umbrellas are available for a small fee, and light meals can be enjoyed in a beautiful setting.
The beach is steeped in history, with its name 'Red Castle' alluding to the presence of prehistoric settlements nearby. While there isn't an actual castle here, the area is rich in archaeological significance, adding a layer of intrigue to its natural beauty.
Alonissos itself is a tranquil island, known for resisting mass tourism and offering a genuine Greek experience. The island is home to the National Marine Park, which attracts nature lovers and those seeking a serene escape from urban life.