Lake Bolsena

The lake has an oval shape typical of crater lakes. The long axis of the ellipse is aligned in a north–south direction. The bottom is roughly conical, reaching a maximum depth at a point in the middle. The entire lake is surrounded by hills on the flanks and summits of which are the comuni. The watershed was home to 22,000 permanent residents in 2004, and 35,000 in the summer season. Elevations on the north of the lake are the highest, rising to , some above the lake's surface. On the northern rim of the caldera is San Lorenzo Nuovo ("New Saint Lawrence"), which was moved from an older site (a hypothetical San Lorenzo Vecchio, "Old Saint Lawrence") further down the slope to avoid malaria. The northern shore of the lake once featured marshes, breeding grounds for the mosquitos that carry the disease. Currently it is agricultural. At the site of old San Lorenzo are Etruscan antiquities. To the north of San Lorenzo Nuovo and the caldera rim is Acquapendente. The hills to the east are to . Bolsena extends upward on the northeast shore, with Orvieto further to the northeast, at the edge of the volcanic region. On the southeast of the lake is Montefiascone at an elevation of , up on the ridge of Montefiascone caldera. To the south of the lake is Marta, on the right bank of the Marta River, sole effluent of the lake. The shore there is straight and developed. Elevations are within of the lake. Next to Marta are Valentano and Capodimonte, the latter being built on and around nearly the only headland on the lake, which forms a protective harbor. About to the south are Tuscania and Viterbo, the latter being the regional capital. From Valentano north is the Latera caldera, a shallow crater perhaps half the size of Lake Bolsena, with Lake Mezzano (usually too small for the map) at the western end. On its north rim is Latera. The floor of the caldera is mainly agricultural although the uncultivable rocky lava flows have been left forested. Although the hills on the west side of Lake Bolsena are only slightly higher than those on the south, the terrain is somewhat too rough for settlement. Fields extend as far as they can into v-shaped valleys and there is no flat shore. The hills to the north loom over the lake. At their western edge are Grotte di Castro and Gradoli. , at the foot of the northern hills. and Latera on the western shore. Center is Bisentina, with Martana to the right and the headland of Capodimonte to the right of it. The city on the left of the far shore is Bolsena . Bolsena is visible in the far distance, as well as the two islands on the left. ==Geology==

Lake Bolsena is at the center of the Vulsinii (or Vulsino) Volcanic District of the Roman Comagmatic Region. The lake formed when a circular area collapsed after the depletion of the underlying magmatic chamber that fed the whole volcanic district. Although it is generally known as a volcanic lake, like its southern neighbor Lake Bracciano it is not a crater lake nor does it occupy a caldera. The major calderas of the area are found close to the lake's rim (Latera to the west and Montefiascone to the south east). ==Islands==

Bisentina Bisentina has an area of , making it the lake's largest island. It is accessible via a ferry service from Capodimonte. On the island are groves of evergreen oaks, Italian gardens, and various monuments: the church of Saint James and Saint Christopher with its cupola built by the architect Jacopo Barozzi da Vignola; the Franciscan convent; the Rocchina, a small temple dedicated to Saint Catherine. The latter was constructed in an octagonal floorplan by Antonio da Sangallo, over an Etruscan columbarium previously erected on a rocky outcrop on the lake. Another monument, the chapel of the Crucifix, contains frescos of the fifth century. The Malta dei Papi, a former prison for ecclesiastics found guilty of heresy, was shaped from a small cave with a trapdoor placed at a height of . Mysterious in its creation, located under Mount Tabor, the highest point of the island, cited by Dante Alighieri as a life-prison. Malta dei Papi is a deep tunnel dug into the tuff at the end of which there is an underground chamber of about 6 meters built around a well, and above which there is a circular opening used to collect water. The waterproof plaster found on its inside walls reveal that the structure was used as a cistern in Roman Times. However, its origin is probably much older than that and linked to the volcanic thermal waters that flow underneath. Forgotten after being turned for a long time into a stage of atrocities as a prison for heretics, this chamber became subject of occultist conversation in the late 19th century in Madame Blavatsky’s theosophic society, who considered this place to be one of the secret entrances to the underground kingdom of Agarthi, "the Inaccessible". The Etruscans and the Romans left few traces of their stay on the island. In the 9th century it provided refuge from the incursions of the Saracens. About 1250, it became the property of the lord of Bisenzio, who abandoned it and burned it following disagreements with the inhabitants of the island. In 1261, Urban IV reconquered it. The island was destroyed again in 1333 by Louis IV of Bavaria, accused of heresy and excommunicated by the pope. The property of the Farnese family from 1400 onwards, it had a period of prosperity and was visited by many popes. In 1635, it was governed by Odoardo Farnese, duke of Castro, who entered into conflict with the Church, resulting in the total destruction of Castro. The two islands returned to the Church's control but were soon ceded again. The princess Beatrice Spada Potenziani, wife of the duke Fieschi Ravaschieri, owned it until its sale to a foundation in 2017. Martana Located opposite the town of Marta, the island of Martana is reputed to have once guarded the relics of Saint Christine to keep them from falling into the hands of the barbarians. Later, it is said that, during the dominion of the Goths, their queen Amalasuntha was assassinated there. The island is currently private property and no visitors are allowed. ==Marta outlet==

The Marta is an emissary of Lake Bolsena to the east of the community of Marta, emptying into the Tyrrhenian Sea. After passing through Marta, Tuscania and Tarquinia, it reaches the sea near Lido di Tarquinia. Salt pans have been constructed between its mouth and that of the Mignone river. ==Comuni bordering the lake==

The following comuni are situated on the shore of Lake Bolsena: • Bolsena • Montefiascone • Marta • Capodimonte • Valentano • Gradoli • Grotte di Castro • San Lorenzo Nuovo Each has a designated length of beach for summer swimming. Some of these have facilities such as cafés, restaurants and boat rentals. Other nearby towns are Sorano, Pitigliano, Acquapendente and Orvieto, with Onano to the northwest. ==Films==

• Tucci in Italy, Season 1, Episode 5 (2025) ==See also==