The Castle of Arraiolos, also known as Paço dos Alcaides, is located in Arraiolos, in the region of Évora, on top of the São Pedro Hill, towering over the town, and allowing a 360º view of the vast Alentejo plain. Built around 1305, during the reign of D. Dinis, it was donated in 1387 to D. Nuno Álvares Pereira, called Count of Arraiolos. It was remodelled in the reign of D. João IV, and ended up abandoned and, finally, in ruins after serious damage caused by the 1755 earthquake. It is one of the few in the world to have circular architecture. In 1910 it was classified as a National Monument and restoration work was carried out by the Portuguese Directorate-General of Buildings and National Monuments (Direção Geral dos Edifícios e Monumentos Nacionais).