Castle of Amieira do Tejo The Amieira do Tejo Castle is a Portuguese castle in the civil parish of Amieira do Tejo , municipality of Nisa , in the antique district of Portalegre , approximately 200 kilometres from the city of Lisbon History . In 1232 , owing to a regal charter issued by King Sancho II , the dominion of the Knights Hospitaler expanded their influence into the south ; the religious order expanded into the villas of Amieira , Gavião and Crato . In Crato , they carried out construction projects , to establish their institutional seat , just after the donation . The construction of the castle in Amieira only developed a century after the Hospitalers had taken possession of the territory . Its construction was the responsibility of Álvaro Gonçalves Pereira , son of the Archbishop of Braga Gonçalo Pereira , prior of the Order of the Hospital and father of the future - " constable of the kingdom " , Nuno Álvares Pereira . It was Gonçalo Pereira who had originally been responsible for transferring the Order from Leça do Bailio to Crato e Mártires ( in 1356 ) . The castle of Amieira was constructed as part of the settlement ' s place in the new function of the Order : to assist the travelling pilgrims . Three years following this change in roles , King Peter I visited the fortress , whose construction was already quite advanced . But , by 1362 , the project had not been concluded : Álvaro Gonçalves Pereira had taken a lot of pacience in the construction and evolution of the castle , until his death in 1375 . The fortress suffered various modifications over the centuries . During the reigns of King John II and King Manuel , there were remodelling to adapt the structure to the new military requirements . Simultaneously , it served as a prison , due to its excellent construction . Losing its military function , due to the change in the lines of defence over time , the castle fell in importance . In the 18th century , a great part of the historical structure was abandoned , and part of the fortress was adapted for civil residences . By this time , the prison tower was partially recuperated , but its military functionally was completed abandoned . In the 19th century , the central courtyard was converted into a local cemetery , which continued to be used in this form until the 1940s , when the DGEMN promoted the castles reconstruction . It has been listed as a National monument since 10 November 1922 . Architecture . The castle is accessed from the Praça de Nun ' Alvares , and can be reached from the EN 359 motorway , or alternately from the A6 , existing from Torres Novas , IP6 until Abrantes , and the EN 118 roadway towards Nisa ( exiting in Arez ) . The castle is found in an urban environment , isolated in a terrain with manicured gardens and space for parking . It is sited on a parcel that is relatively planar , except on the western limits where it is inclined , with houses to the north and east , while agricultural fields and orchards to the south and west . The Castle of Amieira is the prototypical Gothic Portuguese castle . It is located on a relatively low hilltop , in a rectangular plan consisting of a walled courtyard with four towers located at its apexes . The prison block which is located in the largest of these towers , is located above the principal entrance to the fortress . In comparison to the isolated Romanesque cell blocks , the tower also served the defence of the castle , in an area that was most vulnerable . The central courtyard , which is an ample space , allows the space for placement of troops and easy movement . The castle also provides two levels of complimentary defence , as indicated in 14th century documentation : a pit ( which has not survived to today ) , and a barbican to the rear of the fortress , that formed a secondary landing in case of siege . Encountered by one of the towers , but outside its walls , is the Chapel of São João Baptista , which dates back to 1556 ( from its doorway inscription ) . The interior has a vaulted decorated ceiling with , with an image of the patron saint ( Saint John ) and a retable from the late Renaissance period .