Castle of Belver The Belver Castle is a Portuguese castle in the civil parish of Belver , municipality of Gavião , antique district of Portalegre , in northern Portugal . History . Belver was the first castle and most important to be constructed by the Hospitalers in Portugal during the Middle Age s . It was built in order to defend the access - way along the Tagus River , and donate by Sancho I under the condition that a castle be constructed . In 1194 , King Sancho conceded this region of the Northern Tagus River , then known as " Guidintesta " , or " Guidi in testa " ( or still of Costa ) , to Afonso Paes , prior of the Order of the Hospitallers . By so doing , the King hoped to stabilize the Christian - Muslim frontier along the Tagus River , leaving the Templar to almost monopolize their power along the frontier lands . The King began referring to the construction of the Castle and the surrounding as Belver . In his later testament , King Sancho transferred the title of the Castle to the Hospitalers . By 1210 , construction was far enough advanced to allow the permanent occupation and defence . The testament while identifying its existence , also made it clear that the Castle was one of the six repositories of the nation ' s wealth , thusby providing ample proof of the Castle ' s defences , albeit located in a frontier outpost . The final construction was completed in 1212 . Between 1336 and 1341 , Belver fell under the most important command of the Hospitallers , while still not seat nor official House , which continued to reside in the town of Leça do Balio . Even as the head of the Order transferred his rule to the parish of Flor da Rosa , in the municipality of Crato , creating the priorship of Crato , the Castle of Belver ( and its community ) did not progress more than a provincial stronghold . The fortress remained intact over the following centuries , preserving many of the primitive Romanesque military motifs of the period . In fact , the castle was systematically adapted to military conditions of the time , while garrison accommodations were improved . After becoming King , John I of Portugal renewed the Castle ' s important military role , and in the face of Castilian conflicts , had the Castle ' s defenses expanded and rehabilitated , under the direction of Nuno Alvares Pereira ( in 1390 ) . In the 16th century , the Chapel of São Brás , was completed . Similar renovations occurred in the 17th century , by Cosmander . By the 19th century , the Castle , apart from its imposing form above the parish of Belver , was completely forgotten , becoming a shelter for the settlement ' s cemetery in 1846 . The 1909 earthquake caused major damage to the fortifications , but only resulted in major re - construction between 1939 and 1946 , when the DGEMN - " Direcção Geral dos Edifícios e Monumentos Nacionais " also continued to work on the Castle grounds annually , rehabilitate , demolish and erect major facets of the Castle . Similarly , in 1976 , the walls and roof were repaired , while the door to the chapel and alter were renovated , and in 1986 , while lighting was updated on the grounds , the roof was repaired once more . In 1987 - 1988 , repairs to the donjon ( plaster , masonry and pavement ) were completed . On 1 June 1992 , the property was transferred to the IPPAR " Instituto Português do Património Arquitectónico " , under decree - law 106F / 92 . The institution , before being subborned into the IGESPAR was responsible for a complete restoration and conservation of the Castle . Architecture . Located on the periphery of the village of Belver ( isolated on the south - west corner ) , alongside the right margin of the Tagus River , at the confluence of the Ribeiro de Belver , overlooking a panorama , that includes olive orchards to the east and south - east . Its plan includes a principal rectangular keep circuited by walled parapets , that encircle the space on the hilltop , and Renaissance - era chapel . The castle gates are located on the south face , anticipated by a staircase of masonry stone , and flanked by two towers , whose design would be used by King Denis . Beyond the entrance is a triple doorway of rounded arcs , which now provides entry onto the grounds . Central to the completed structure is the donjon or keep , whose first floor provides a grated access - way to the dungeons . The keep ' s entrance - hall has a rectangular window and staircase that provides access to the second floor . The second - floor hall , also with a rectangular window and arched doorway , leads onto the vistages of the veranda , while another doorway leads to the superior floor access to the battlements . The walls and battlements which encircle the Castle follow a semi - circular oval around the keep , and are covered in parapets and turrets , with strategically place cubicle towers located around the entranceway and in each direction of the compass . The " Traitor ' s Gate " , the secondary access to the castle , is located on the cliff side of the structure , guarded by a round tower . Vestiges of the alcalde ' s residence and garrison are located in the south - east , south and south - west parts of the castle , in the space occupied by the three archways . To the north is the remains of the garrison ' s cistern , constructed during the remodelling of the castle by Nuno Álvares Pereira . Near the centre of the Castle , and in the east , is the Chapel of São Brás , alongside the keep . In the interior of chapel is a high - alter , with a number of busts and reliquaries from Palestine , presented by the Great Prior of Crato to Prince Luís , son of Manuel I of Portugal . Italian counterparts , and decorated with the grande importance associated with the religiosity of the legendary reliquaries of the Holy Land .