However, rainfall can be abundant, especially in autumn and spring, due to the orography of the Riviera di Levante. In the municipal area, the weather station is located on Island of Palmaria, where data can be considered similar to those occurring in Porto Venere and the surrounding areas. The area of Portovenere-Palmaria Island is the only point behind in the Ligurian Sea between the Isle of Elba and the islands of Hyères, France. Hence the strategic role in the history of seafaring. Economy In the municipality of Porto Venere, in Panigaglia, into the Gulf of Spezia, there is a regasification plant, thanks to which it can import by sea, in the liquid state, natural hydrocarbon gas such as liquified natural gas. Portovenere's economy focuses on tourism. Hotels, bed and breakfasts, guest houses, and residences have become more important in recent years. The popular shopping promenade in the Doria quay and the picturesque Alley and panoramic views to the church of St. Peter and the Doria Castle. The harbor of Portovenere, although the smallest of Liguria, is always sold out in the summer season and also hosts many celebrities. Main sights The Church of St. Peter, consecrated in 1198. It was built over a pre-existing 5th-century Palaeo-Christian church, which had rectangular plan and semicircular apse. The new part, from the 13th century, is marked externally by white and black stripes. The Romanesque church of St. Lawrence, erected in 1098 by the Genoese probably occupies the site of ancient temple dedicated to Jupiter. The church was damaged by a fire in 1340 and by the Aragonese attack in 1494, and was further restored in 1582. The Doria Castle, an example of Genoese military architecture. The castle has changed over the centuries in response to developments in military technology. The castle consists of two parts, a 15th Century upper section and a later (post-cannon) lower section. The lower section contains the Sala Ipostila, a hall built on the site of ancient Greek temples. The upper section contains the Casa del Catellano, the home of the commander of the castle and sits above the Sala Ipostila. During the Napoleonic period after 1807, the Castle saw service as a political prison. The Grotta dell'Arpaia (now collapsed), known as Byron's Grotto, from which the English poet Byron swam across the gulf of La Spezia to San Terenzo to visit Shelley in Lerici, in 1822. The medieval