The Bridge of Gran Arvou spans the Rû Prévôt irrigation canal, and includes a large corridor covered by flagstones.
The Grand Arvou is an arch bridge, with a span of 68.5 m and an elevation of 13,60 m between the arch's top and the ground; the distance between the roof and the base of the arch is 10,5 m. The bridge is built in mortar and small incoherent stones, with partial plastering. The plan is irregular, with a general trapezoidal shape, but without the main parallel side; the walls's thickness varies from 50 to 55 cm. The roof is covered by flagstones, which helped it resist to the centuries.
In the late 13th-early 14th century, there was a series of programs aiming to improve the irrigation level in Aosta Valley, due to increased demand of animal husbandry. One of this was the construction of canal, the Rû Prévôt, by will of Henry of Quart, provost (hence the name) of the Aosta Cathedral. This included also the couple of bridge-aqueducts which are now visible.
The income of the canal exploitation was later acquired by the Dukes (later Kings) of Savoy. In the 20th century, the canal was mostly channeled into pipes.
References:Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.