Agios Dimitrios
You'd have to try very hard to find a Sporades beach, or in fact, a Greek beach with waters as crystal clear as at Agios Dimitrios, on Alonnisos. The almost spit-shape white pebble beach is long, uncrowded, and has a stupendous view of Peristera island directly opposite. The water is shallow and calm, and the beach is lined with just a handful of picturesque palm-leaf umbrellas and sun beds to rent. Behind the beach, along a tree-lined road, you'll find a couple of beach restaurants serving delicious traditional Greek dishes. Amenities: parking (free); food and drink. Best for: solitude; swimming; walking.