 The firsts to preserve the remnants began on 16 November 1973.At that time, the "Junta Nacional de Educação" ("National Junta for Education") proposed the classification of the castle a "Property of Public Interest".This was superseded on 6 March 2006, by the DRPorto, which proposed the establishment of a Special Protection Zone for the property, leading to the classification of the property as a "Sítio de Interesse Público" and incorporating it into its own Special Protection Zone on 10 January 2014 (Diário da República, Série 2, 7, Ordinance 20/2014).