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:
Frösöstenen is the northern-most raised runestone in the world and Jämtland's only runestone. It originally stood at the tip of ferry terminal on the sound between the island of Frösön and Östersund. The stone dates to between 1030 and 1050. It has now been relocated to the lawn in front of the local county seat due to the construction of a new bridge, between 1969 and 1971, on the original site.
Frösö runestone inscription means: Austmaðr, Guðfastr's son, had this stone raised and this bridge built and Christianized Jämtland. Ásbjörn built the bridge. Trjónn and Steinn carved these runes.