Tourbillon Castle was built sometime between 1290 and 1308 by the Bishop of Sion, Boniface de Challant, as his principal residence. After Boniface died in 1308, his successor Aymon II de Châtillon probably finished the castle. In 1352 the Upper Valais revolted against Bishop Guichard Tavel. Led by Peter de la Tour, in November of that year, they marched on Sion, burned the town and unsuccessfully besieged the castle. In 1373, the Prince-Bishop bought Majorie Castle and moved his residence off the rocky spire. However, Bishop Tavel was not able to enjoy his new palace for long. In 1375 he was captured and murdered by rebels led by Peter's son, Anton de la Tour, in 1375.
Tourbillon became the Prince-Bishop's summer residence and remained a visible symbol of secular and ecclesiastical power. In 1384 a group of rebels attacked Sion and captured Tourbillon and Majoria. Bishop Eduard of Savoy had to request soldiers from Count Amadeus VII of Savoy and Bern to retake his castles.
A large part of the castle was destroyed during the Raron affair in 1417 and Bishop Wilhelm V of Raron had to flee to Bern. The castle was then rebuilt in the 1440s to 1450s by Bishop Guillaume VI of Raron. As part of the reconstruction, the chapel was repaired and painted with Gothic frescoes which are still visible. It remained the administrative center of the diocese but in later centuries the military importance of the castle decreased. On 24 May 1788, a gigantic fire in Sion reduced the castle to ashes. The Bishop planned to rebuilt Tourbillon, but the revolutions sweeping through Europe ended the plans. The castle was excavated and restored in the 20th century.
The castle ruins are located on a rocky spire above the city of Sion. Reaching the site requires climbing steep stairs that wind around the hill. The castle is surrounded by a ring wall that follows the irregular top of the spire. On the west side of the complex is a pentagonal fortified building. The 15th century chapel is located in the south-east corner. The chapel's frescoes are still intact despite the fire that destroyed the castle. A slender watch tower still stands in this corner as well. The southern wall is fortified with a square gate house. The keep is rectangular and many of the interior walls still stand.References:
Monte d"Accoddi is a Neolithic archaeological site in northern Sardinia, located in the territory of Sassari. The site consists of a massive raised stone platform thought to have been an altar. It was constructed by the Ozieri culture or earlier, with the oldest parts dated to around 4,000–3,650 BC.
The site was discovered in 1954 in a field owned by the Segni family. No chambers or entrances to the mound have been found, leading to the presumption it was an altar, a temple or a step pyramid. It may have also served an observational function, as its square plan is coordinated with the cardinal points of the compass.
The initial Ozieri structure was abandoned or destroyed around 3000 BC, with traces of fire found in the archeological evidence. Around 2800 BC the remains of the original structure were completely covered with a layered mixture of earth and stone, and large blocks of limestone were then applied to establish a second platform, truncated by a step pyramid (36 m × 29 m, about 10 m in height), accessible by means of a second ramp, 42 m long, built over the older one. This second temple resembles contemporary Mesopotamian ziggurats, and is attributed to the Abealzu-Filigosa culture.
Archeological excavations from the chalcolithic Abealzu-Filigosa layers indicate the Monte d"Accoddi was used for animal sacrifice, with the remains of sheep, cattle, and swine recovered in near equal proportions. It is among the earliest known sacrificial sites in Western Europe.
The site appears to have been abandoned again around 1800 BC, at the onset of the Nuragic age.
The monument was partially reconstructed during the 1980s. It is open to the public and accessible by the old route of SS131 highway, near the hamlet of Ottava. It is 14,9 km from Sassari and 45 km from Alghero. There is no public transportation to the site. The opening times vary throughout the year.