The Giants' grave of Su Mont'e s'Abe is an archaeological site located in the municipality of Olbia. Like other giants' tombs of Gallura, it was built in two main phases of construction. In the first stage, during the period of the Bonnanaro culture, it was built an allée couverte tomb; later, in the second phase, during the age Nuragic age (1600 BC approximately), the allée couverte was transformed into a giants' tomb with the realization of the exedra and the erection of the central stele of which few traces remain today.
The tomb, which measures about 28 meters in length and six in width, was excavated and restored in the 1960s.
References:Ogrodzieniec Castle is a ruined medieval castle originally built in the 14th–15th century by the W³odkowie Sulimczycy family. Established in the early 12th century, during the reign of Boles³aw III Wrymouth, the first stronghold was razed by the Tatars in 1241. In the mid-14th century a new gothic castle was built here to accommodate the Sulimczycy family. Surrounded by three high rocks, the castle was well integrated into the area. The defensive walls were built to close the circuit formed by the rocks, and a narrow opening between two of the rocks served as an entrance.
In 1470 the castle and lands were bought by the wealthy Cracovian townsmen, Ibram and Piotr Salomon. Then, Ogrodzieniec became the property of Jan Feliks Rzeszowski, the rector of Przemy¶l and the canon of Cracow. The owners of the castle about that time were also Jan and Andrzej Rzeszowskis, and later Pilecki and Che³miñski families. In 1523 the castle was bought by Jan Boner.