Ventotene is a small island rising like a slanting reef out of the Tyrrhenian sea. The island is thin and less than two miles long, steep and rocky on one side and sloping towards the sea on the other. Rocky, and with no water springs, it was an unpromising place until the ingenious Romans turned up and set to work. With a combination of skilled engineering and slave labour, they dug a harbour out of the island's tufa rock and created a network of rock-cut water cisterns to save rainwater and channel it around the island. A luxurious imperial villa was built on a panoramic headland, and the island, then known as Pandataria, served as an agricultural estate attached to the villa. The grand palace was, however, not destined to be enjoyed by emperors, but used as a place of exile for high-status prisoners. The first was Augustus's daughter Julia, who was sent here on charges, perhaps false, of treason and adultery. The ruined villa is now known as the Villa Giulia, after its most famous resident, although other prisoners were to follow her. Villa Giulia covers the headland of Punta Eolo with an unprepossessing confused mass of low ruined walls. With a guided tour, though, the visitor begins to spot traces of its past glory - fragments of mosaic, painted walls, ruined baths. The other significant Roman remains on Ventotene are its cisterns, whose underground chambers have been used and re-used over the centuries for a range of purposes. Like the villa and Santo Stefano (described below) they can only be visited, at the time of writing, on organised guided tours. Run from the island's archaeological museum, the tours alternate throughout the week; times and days are publicised locally. To be sure of seeing a range of sights, it is best to plan a stay of two or more days. The archaeological museum (Museo Storico Archeologico) is housed in the basement of Ventotene's imposing town hall, the Torre Borbonico, an old Bourbon fortress which dominates the town square. It contains a good collection of artefacts from local shipwrecks and from the Roman villa. Many of the finest sculptures and marbles were removed from the island in later centuries, but the fragments in this museum, including painted stucco decorations, give an idea of the high standard of decor. Other exhibits include a bust of Tiberius (Julia's husband) found in the harbour. Opening times are limited, so visitors should confirm the latest hours on arrival at Ventotene. Ventotene's old Roman port is still in use today. It has been altered over the millennia and the rock chambers cut to store Roman goods are now used by fishermen and diving businesses. Fishing boats and excursion boats use the harbour, and from the quayside you can hire boats or book island tours and trips to Santo Stefano. Visitors can also book diving lessons and excursions with Ciro Sub and Ventotene Diving Academy. Around a corner from the Roman harbour is Ventotene's modern port, a functional and unromantic place where the island ferries dock. Ventotene has one settlement, above the old port. It can be reached on foot from water level by climbing a theatrical yellow-painted zig-zag lane from the Roman port. A curving tarmac road offers a less steep route, winding around another picturesque inlet. The town clusters around the large square Piazza Castello. A selection of the island's services - a couple of food shops, a fabulous bakery and a couple of bar-restaurants - are on this square and the road alongside. Other buildings are strung out along Via Olivi, a road which runs the length of the island. There isn't much traffic on Ventotene, and the narrow Via Olivi offers a pleasant stroll along the island. You may catch glimpses of migratory birds, such as hoopoes. Ventotene's second museum, the Museo della Migrazione, is situated towards the far end of the island and is dedicated to the birds which visit the island. It also has a panoramic terrace from which you can enjoy sea views. Via Parata Grande, off Via Olivi, leads to a viewpoint above the cove of Parata Grande, where a path climbs down to sea level. You can see more of the island's coastline, or visit small rocky coves, by booking a boat trip around the island. Although Ventotene is mostly rocky, there is a very pleasant beach below the town, in a bay called Cala Nave around a headland from the harbour. Excitingly, a tunnel runs through the headland to link the beach with the port. Smooth rock platforms by the headland offer more opportunities for sunbathing and swimming. Around the foot of the lighthouse, you can spot part of a Roman system of fisheries cut into the rock. Between the lighthouse and the Torre Borbonico is a pleasant park which encloses the ruins of another Roman villa, with low ruined walls, an archway and more scraps of mosaic. This villa, above the fishery, was built on several levels and part of the lower level now stands on a rock stack out to sea; erosion and quarrying have detached this section from the other surviving remains of the villa. The island of Santo Stefano, around a mile from Ventotene, makes an interesting excursion from Ventotene. Boat tours from the Roman port may take you around the island and possibly visit the Vasca Giulia, a Roman-era rock-cut basin by the sea. At the time of writing, though, landing on the island is forbidden - unless you visit with a guided tour of the abandoned prison. Boatmen at the Roman port ferry the visitors across from Ventotene to Santo Stefano, where a guide leads the group up steep steps to the prison which dominates the island. This prison, the Carcere Borbonico, is a monument falling into sad disrepair. Guided tours are in Italian and last around three hours, with lengthy talks on the history and development of the prison. Among the political prisoners incarcerated here by Italy's Fascist regime was Sandro Pertini, who later became president of Italy.