The Lake of Bolsena (Viterbo) is the largest volcanic lake in Europe and the fifth largest lake in Italy having a circunference of 42 km. The lake, situated 305 m above the sea level, is 12 km in diameter and has a maximum depth of 152 m. Two islands, Bisentina and Martana, emerge from its limpid waters. Bisentina island with its seven Oratories, the convent of St. James and St. Christopher and its beautiful gardens is considered the major tourist attraction of the lake, and was chosen to be the summer residence of the Popes in different eras of its history. Martana island still preserves the remains of the fortress in which queen Amalasunta, the daughter of king Theodoric of the Goths, in 535 was imprisoned and killed on the orders of her cousin and husband Theodorat. The lake is rich in history as are the eight charming villages that nestle around its shores. In recent years the lake has brought to light numerous archaeological finds, including a pirogue carved from a single trunk, currently on exhibition in the Museum of Capodimonte.