The Skiathos Beach Day Route Planner sequences the beaches you pick along the island's single paved south-coast road and returns the driving distance, time, car class and parking deadline. Skiathos Town to Koukounaries is about 12 to 13 km, roughly 20 minutes in light traffic (a non-stop run is nearer 12 to 15 minutes; allow about 21 with the beach-junction turn-offs). A classic south hop of Achladies, Vromolimnos and Koukounaries is about 25 km round trip and around 42 minutes' driving off-peak, but closer to 1.5 hours at August midday. Any small car such as a Toyota Aygo, Yaris or Clio handles the paved south coast, with local quotes around 22 to 35 euros per day; arrive by 09:30 to 10:00 for the first-filling beaches in July and August, because the south-coast car parks at Koukounaries, Vromolimnos and Agia Paraskevi hit 90 to 100 percent capacity by 11:00. Vromolimnos is the exception worth knowing: it empties after 16:00 and stays open latest for sunset. The north coast is different. Adding Kastro to a Koukounaries day pushes the trip to about 49 km, needs a compact driven with care or a 4x4, voids standard CDW insurance on the dirt section, and requires a full tank because there is zero fuel north of the south ring road. Kastro is 12 km of paved road to the Panagia Kardasia church where the tarmac ends, then rough dirt and a 500 metre walk. Mikros Aselinos and Kechria/Ligaries need a 4x4. Lalaria is boat-only from the Old Port and is often cancelled by the Meltemi wind. Under the 2026 Greek Road Traffic Code (Law 5209/2025) fines follow the driver, the urban limit is 30 km/h, and illegal parking costs 80 euros plus on-the-spot licence-plate removal.