Skiathos

Where it sits. Skiathos is the westernmost and most visited of the Northern Sporades, an island of about 48 square kilometres lying only a few kilometres off the Magnesia coast of Thessaly. It is small enough to drive end to end in half an hour and dense enough to have kept more than sixty beaches in that space, most of them on the sheltered south coast where a single road strings together bay after bay. The interior is pine forest over low hills topped by Karafiltzanaka at 433 metres; the northern shore is a different island altogether, exposed, cliff-bound and reachable in most places only by boat. Around 6,600 people live here permanently, a figure that multiplies many times over in August.

Airport, arrivals and the reason everyone comes. Skiathos has the only airport in the Sporades, and its runway of roughly 1,600 metres is built across a low neck of land with the sea at both ends and a public road running immediately behind the threshold. The result is one of the most photographed approaches in Europe, with jets crossing the road at a few metres and a crowd of spectators standing in the blast on the beach behind. That runway is why the island became a package destination in the 1970s while its neighbours stayed quiet, and it remains the gateway for Skopelos and Alonnisos as well: most visitors to the other two islands land here and transfer to a hydrofoil at the old port.

Lalaria and the north coast. The single most striking place on the island is Lalaria, a beach on the northern shore made entirely of white limestone pebbles ground smooth by the swell, backed by pale cliffs and pierced at one end by a natural rock arch known as Tripia Petra. There is no road; boats leave the old port each morning in season and the landing is on open water, so the trip is cancelled in a northerly wind. The same excursion usually takes in the Skotini, Galazia and Chalkini sea caves and the abandoned medieval town of Kastro on the northern headland, which was the island's main settlement from the mid-fourteenth century until 1829, when the population moved back to the modern harbour. Only a few churches and a stretch of wall survive up there, but the site is spectacular and the walk in from the road end is an hour of good coastal path.

On screen. Skiathos was one of the two Sporades bases for Mamma Mia! in the summer of 2007, along with Skopelos, and the production's third Greek location was Damouchari on the mainland Pelion coast. This trips up a great many visitors, who arrive expecting to find the chapel and the beach bar here. They are not on this island: the wedding chapel of Agios Ioannis sto Kastri and the beach at Kastani are both on Skopelos, an hour east by hydrofoil, and the harbour village where the crowd dances down to the quay is Damouchari. What Skiathos supplied was the shooting base and the gateway — the airport that flew the cast and crew in, the port they worked out of, and the western Sporades seascape that appears throughout the film.

What the island is like on the ground. Skiathos Town wraps around a double harbour split by the wooded islet of Bourtzi, which carries the ruins of a Venetian-era fortification and now an open-air theatre and cafe. The lanes behind the waterfront are steep, tightly packed and busy well past midnight in season. The writer Alexandros Papadiamantis, one of the founders of modern Greek prose, was born here in 1851 and died here in 1911; his single-storey family house near the harbour is now a small museum and gives an unvarnished picture of nineteenth-century island life. At the south-western tip, Koukounaries is the celebrated beach — a 1,200-metre arc of fine sand backed by an umbrella-pine forest and the Strofilia lagoon, a protected wetland with tortoises, herons and a marked path around it. Banana, Agia Eleni, Vromolimnos and Megali Ammos fill in the rest of the south coast.

Getting there and timing. Direct charter and low-cost flights run from across northern Europe between May and October; ferries and hydrofoils connect to Volos, Agios Konstantinos and Mantoudi on Evia year-round, and to Skopelos and Alonnisos several times daily in season. The bus along the south coast runs at high frequency in summer and is the cheapest way to work through the beaches. July and August are hot, full and expensive; June and September give the same sea temperature with far more room. From November the airport traffic stops, most of the town closes, and the island returns to its 6,000 residents and a hard northerly wind.