It is located in the city, municipality and district of Guarda, being the highest city in the country, located in the region of Central Portugal and sub-region of Beiras and Serra da Estrela
 
Guarda Castle, in a dominant position over the highest city in the country, stands at 1,056.3 meters above sea level.

Despite being largely uncharacterized by interventions particularly from the 19th century onwards, the remaining traces of its old walls still define the urban limits in some sections.
History of Guarda Castle
 
The original occupation dates back to an old fort on one of the sides of the Serra da Estrela and in the 1st century, at the time of the Roman occupation, this village, close to a road junction, developed under the name Lancia oppidana.

The construction of a fortified line covering the region at the turn of the 13th century in which Sancho I of Portugal (1185-1211) transferred the diocese of Egitânia gave new life to the city.

It is to this sovereign that the first charter of the city is due (Guarda was already a city by charter of November 27, 1199) and to whom the beginning of the first castle in a dominant position over the city is attributed, dating back to the so-called Torreão of 1187.

During the reign of Afonso II of Portugal (1211-1223), the Keep (1290) and the northern section of the walls next to Porta d''''El Rei were begun.

The Reforms carried out during the reigns of Dinis of Portugal (1279-1325), Fernando I of Portugal (1367-1383) and João I of Portugal (1385-1433) reformulated its original appearance.

In general, it is considered that D. Dinis was responsible for the so-called Torre dos Ferreiros, built with stone from the Church of Nossa Senhora da Consolação as the eastern section of the walls and the so-called Porta da Erva.

D. Fernando is responsible for some work and the razing of the eastern suburbs and D. João I for completing the northern (next to Torreão) and southern (next to Porta da Covilhã) sections of the walls.

At the beginning of the 15th century, the castle experienced a new construction stage with the so-called New Tower next to Porta da Covilhã.

In the 18th century, the defensive set was made up of the walls where they were torn apart: the Porta Nova (or Porta da Covilhã), the Porta do Curro and the Porta Falsa to the north, the Porta da Erva (or Porta da Estrela) next to the Torreão, the Porta d’El Rei and the Porta Falsa to the north and the Porta dos Ferreiros and the Torre de Menagem (to the south), the Torre dos Ferreiros and the Torre Nova (or Covilhã Tower).

In the 19th century, due to the expansion of the urban fabric, the medieval walls that served as a foundation for the opening of streets and the construction of buildings began to be demolished.
Features of Guarda Castle
 
The castle has an organic irregular polygonal plan in granite masonry that is abundant in the region and its architecture combined elements of the Romanesque and Gothic styles.

The complex comprised two main spaces: the citadel (alcáçova) dominated by the Keep, the almedina delimited by the fence and some sections of these walls remain: three to the east: from Rua Tenente Valadim to Torre dos Ferreiros, on Rua Lopo de Carvalho, and from Porta da Erva to Torreão on Avenida Firefighters Voluntários showing traces of the ruins of the latter, two, to the north: on Avenida Firefighters Voluntários, on Travessa do Povo next to Porta d''''El Rei and to the west: from Rua Salvador do Nascimento, integrating the so-called Porta Falsa.

The Keep, with an irregular pentagonal plan in Gothic style, stands on top of a hill based on granite mound.

The so-called Old Tower, isolated from the walls, with a polygonal plan with a round arch window, characterizes the oldest enclosure around which the fortress was built.

The Ferreiros Tower has a quadrangular plan with a double elbow door with the respective beginnings of attached sections, and features one of the Passion Steps, part of the Via Sacra.

The doors cut into the walls stand out: Porta da Erva, Porta do Sol or Porta da Estrela, to the east it displays distinct profiles inside and outside the back.

In the first it forms a round arch with irregular voussoirs and in its corresponding pointed arch with traces of having originally been wider and also round.

The Porta dos Ferreiros to the east consists of an elbow entrance, protected by the quadrangular tower, with two access bays: one on the west side with a lowered arch on the intrados and a perfect round arch on the extrados surmounted by a walkway.

Porta da Covilhã and Porta dos Curros, the furthest away in the urban fabric, should have existed since the initial construction, since Rua Direita, the town's main thoroughfare, runs between them.