Achalm is a ruined castle located above the towns of Reutlingen and Pfullingen. Situated on the top of a hill at the edge of the Swabian Alb the ruins of the 11th century castle are topped by a look-out tower from 1838.
Achalm Castle was built around 1030 by Gaugraf Egino and Rudolf of Achalm. The name Achalm appears to refer to a nearby stream, the Ach which comes from the River Alm. The castle was expanded in the 11th Century with a second tower. However the von Achalm family died out shortly thereafter. The castle passed through several owners including the House of Welf. In 1234 the son of the Holy Roman Emperor Frederick II, King Henry VII, rebelled against his father, the Emperor. The owner of Castle Achalm, Heinrich of Neuffen, sided with the rebellious King Henry VII. Following the Emperor's victory over his son Henry VII, Castle Achalm became the personal property of the Emperor's family, the House of Hohenstaufen. Castle Achalm remained a Hohenstaufen property for a time. The castle then passed into the control of the House of Württemberg. In 1377 Graf or Count Ulrich of Württemberg marched from the castle to attack the town of Reutlingen. While he besieged the city, troops from the Swabian Cities League marched to defend the city. Ulrich's troops were defeated and Reutlingen remained a Free Imperial City.
Over the following centuries, the castle began to lose its military value and began to collapse. During the later years of the Thirty Years' War, in 1650, the castle was partially destroyed to prevent enemy forces from using the castle for shelter. Later the stones were removed to build houses in the village. In 1822 the future king and emperor William I had a stone look-out tower built on the foundation of the old tower. The tower was repaired and renovated in 1932 to prevent it from collapsing.
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.