The upper castle of Arnad is mentioned first time in a papal letter in 1207, but there is no information about its origins or first owners. It was probably built by Saverio di Arnad in the late 12th or early 13th century.
The next owners, Vallaise family, lived in the castle throughout the 14th century. Due to the inadequacy of the structure and the lost military function, the castle was abandoned in the 15th century.
Today the castle lies in ruins.References:
The trulli, typical limestone dwellings of Alberobello in the southern Italian region of Puglia, are remarkable examples of corbelled dry-stone construction, a prehistoric building technique still in use in this region. These structures, dating from as early as the mid-14th century, characteristically feature pyramidal, domed, or conical roofs built up of corbelled limestone slabs. Although rural trulli can be found all along the Itria Valley, their highest concentration and best preserved examples of this architectural form are in the town of Alberobello, where there are over 1500 structures in the quarters of Rione Monti and Aja Piccola.
The property comprises six land parcels extending over an area of 11 hectares. The land parcels comprise two districts of the city (quarters or Rione Monti with 1,030 trulli; Rione Aia Piccola with 590 trulli) and four specific locations.
Trulli (singular, trullo) are traditional dry stone huts with a corbelled roof.