The Castle of Monopoli, surrounded by the sea and located on a peninsula, was built first as a stronghold and later changed into noble house. It was originally built as part of coastal strongholds by Holy Roman Emperor Frederick II and later fortified by the Angevins. In 1552 it was once again reinforced by the viceroy Don Pedro de Toledo, at the behest of Charles V. Other important changes were made in 1660, by the Duke of Atri Giovanni Geronimo Acquaviva.
The present appearance dates back to 1660, when the huge cylindrical keep was added, from which it is possible to enter. On the upper part, there are large holes for the cannons, a sign of the original function to protect the town, while the right part, towards the town, appears to be more refined after the works of the 17th century, when it started to be used as house.The castle, reshaped several times over the centuries and used as prison during the first years of the 20th century, was restructured around 1976 and nowadays houses the Archaeological Museum of the Town.
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.