It is located on the street of Santa Cruz do Castelo, in the parish of Santa Maria Maior, in the city of Lisbon, central Portugal
 
Military Castle and urban fence
 
The monument is characterized by being a Military Castle and with an urban fence, it is located on the highest hill in the historic center of the city of Lisbon, and shows visitors one of the most beautiful views over the city and the Tagus River estuary.

The Castelo de S. Jorge is today a place where you can explore the remains of the 11th century Islamic quarter in the Archaeological Site, discover unprecedented views of the city in the Dark Chamber, stroll through the gardens and viewpoint, take a break at the Café do Castelo and participate in guided tours.
The construction of São Jorge Castle in Lisbon
 
In 48 BC, the presumed date of construction of the first fortification was that Lisbon was granted the category of Roman municipality, and in the 10th century the Muslim reconstruction of the fortifications, castles and walls and the Cerca de Moura took place.
The Characteristics of São Jorge Castle in Lisbon
 
The castle defends the ancient Islamic citadel, the Alcazar, with twelve gates opening in its crenellated walls, seven of which face the parish of Santa Cruz do Castelo.

To the outside, a wall gives access to a barbican tower, eighteen towers support and reinforce the walls, through the South Gate, through Rua de Santa Cruz do Castelo you access the Plaza de Armas.

Medieval castle, with an approximately rectangular plan, whose wall, with vertical and thick walls, is crowned by quadrangular merlons without arrow slits, interrupted by 10 towers with a square plan, some having 1 to 2 floors.

Its opening is made at the level of the roof. This is open and runs around the entire wall. A breastplate tower descends from the wall. A barbican reinforces 2 of the sides of the wall, with the main door of the castle being open on one side. The barbican is surrounded on both sides by a moat. The castle is divided in half by a wall interrupted by a tower.

Monument composed of the Castle, the wall that surrounds the Citadel, the Esplanade, the Promenade and the Fences. The castle, at the NO. vertex, is approximately rectangular in plan and is located at the highest point. A straight wall with a battlement and crenellation, facing N.S., divides the castle into two squares of arms with a rectangular plan, with communication through a door, with a broken arch on one side, and a curved lintel on the other. In the square to the W., two stone stairs give access to the wall and, in the wall to the N., the Porta da Traição opens.
The Exterior of São Jorge Castle in Lisbon
 
The S. and E. faces of the Castle are reinforced by a right-angled barbican, which starts from the NE towers. and SW., crenellated, torn by high arrows running along it, a wall accessible by 2 stairs and a jetty on the outer face.

This is opened by two doors, one on the E side, small, with a broken arch, and the other on the S side, preceded by a bridge based on 2 collapsed arches, both giving access to a dry moat that runs between the wall and the barbican. (wall in front of the walls of a fortification and lower than these, built in medieval castles to defend the moat, false-braga)

In the alignment of the bridge is the main door of the castle with a full arch that gives access to a small courtyard, which communicates with the interior through a door with a broken arch on the S. side and a plenary arch (perfect round arch) on the N. Outside the barbican runs a moat with water.

The citadel surrounds the castle on the E. and S. sides and is limited to the N., E. and S. by a belt of crenellated walls, which rises at the NE vertex. of the castle and includes 6 towers, hidden from the outside, and 2 semi-circular cubes.

On the N. section there are 2 doors in a depressed arch, the so-called North door is topped by a tombstone, the Martim Moniz door has an inscription engraved on the wall on the outside, over the arch surmounted by a head of a statue inside a small marble niche representing Martim Moniz.

On the S. section, the main door, Saint George's, is similar to a triumphal arch, with a full arch in rows adorned with marble, on the clasp of which you can read "4 - 4th - 1846 - D. Maria II", and topped with a royal coat of arms. On the side, in bronze letters, a dedication to the Duke of Terceira, Minister of War. This door gives access to the Esplanade.

In this, the Ogival room stands out and to the W. the "Casa do Leão", and from the Esplanade begins the Promenade that surrounds the monument on the W. and N. sides with a parapet.

Its walls crowned by merlons and served by adarves are interrupted by 10 square towers projecting outward, occupying the N., NW wall, a tower covered by a 5-pitched roof with each face torn by an embrasure (a small opening in the walls through which arrows were fired against the enemies, gaps, and a slit to let light pass through).

Inside there is a room, at the level of the wall, with a wooden beam roof. At the center of this wall is a tower covered with a 4-pitched roof, each side of which is torn by a broken arched window.

A door inscribed with a broken arch gives access to the interior whose roof is identical to that of the previous tower.

At the NE vertex. the Cistern Tower, with a crenellated roof and walls torn by embrasures, has a cistern with a stone guard and an iron frame.

On the E. wall, in the center, about 2 m above the apron, a tower with an open roof, crenellated and torn by embrasures, accessed via a narrow stone staircase. At the SE: vertex, there is a taller tower, the Observatory Tower, with an open and crenellated roof, accessed via a 2-flight stone staircase.

In the middle of the S. section is the Ulisses Tower, with a 2-storey plan, with the 1st roof having a groin vault and the 2nd, whose entrance is through a rectangular door open on the N side. It has 3 sides torn by arrow slits and a wooden beam ceiling.

Four pitch roof coverage equivalent to a roof. At the SO vertex. a crenellated tower, whose entrance is through a full arched door, which appears to be missing the closing stone, preceded by some stone steps that rise from the wall.
The Interior of São Jorge Castle in Lisbon (a monument commemorating D. Afonso Henriques)
 
Inside, there is a room with a wooden beam ceiling, the W. wall has 3 towers whose roofs are located above the apron, and access is via a narrow stone staircase on the E. side of the towers, only 3 sides are battlemented with a narrow apron running along them. (battlement: small jagged parapets that guard the tops of towers, fortifications and castles that protect shooters).

There are traces of the Moura and Fernandina fences, most of which are integrated into buildings or tampered with, and of the Moura fence there are traces of 7 sections of wall visible from the public road, 13 towers and cubes, 9 of which are clearly visible and 3 doors or arches.

In relation to the Fernandina Fence there are 8 sections and cubes, 5 of them perfectly identifiable and 1 door or arch, and the INTERPRETATION CENTER in wood and iron with a simple rectangular plan and flat roof.

The monument also offers gardens and viewpoints (with emphasis on the Plaza de Armas with the statue of D. Afonso Henriques), the castle, the citadel and the esplanade, a darkroom (Torre de Ulisses, former Torre do Tombo), exhibition space, meeting/reception room (Casa do Governador) and a themed store for its visitors.
The Castelejo (fortification from Islamic times)
 
The Islamic castle built in the mid-11th century, the fortification is located in the most difficult to access area at the top of the hill, taking advantage of the natural cliffs to the North and West.

The castle's function was to house the military garrison, and in the event of a siege, the elites who lived in the fortress (the citadel) did not have a residence function as is the case with other castles in Europe.

This fortification also preserves 11 towers, including the Keep, the Haver or Tombo Tower, the Palace Tower, the Cisterna Tower and the São Lourenço Tower, located halfway up the slope.

In the second square there are still traces of old buildings and a cistern, and in the North wall there is a small door called Porta da Traição which allowed secret messengers to enter or leave if necessary.
S. Jorge Castle Viewpoint
 
The landscape garden of Castelo de S. Jorge is today the only green space in Lisbon where they dominate, and you can observe the main native species of the Portuguese forest such as cork oaks, olive trees, carob trees, strawberry trees, stone pines and some fruit trees in memory of the old vegetable garden of the Royal Palace of Alcáçova.
Camera Obscura at Castelo de S. Jorge
 
The camera obscura is an optical system of lenses and mirrors that allows you to closely observe the city in real time, its monuments, the river and the hustle and bustle of Lisbon in a 360º view.
Archaeological Center (conditioned access)
 
The Archaeological Center investigates and studies archaeological remains that testify to three significant periods in the history of Lisbon: the first known occupations dating back to the 7th century BC, the remains of the residential area from the Islamic period, from the time of construction of the castle in the mid-11th century, and finally the ruins of the last palatial residence of the old fortress destroyed by the Lisbon earthquake of 1755.
S. Jorge Castle Museum Center (Islamic period from the 11th-12th century)
 
In the Museological Center we can see and appreciate a visitable collection made up of a collection of objects found in the archaeological area, providing the discovery of the multiple cultures and experiences that, from the 7th century BC to the 18th century, contributed to the construction of modern-day Lisbon, with particular emphasis on the Islamic period from the 11th-12th century.
Remains of the Old Royal Palace of Alcáçova (Today Castle of S. Jorge)
 
The entire building complex where the Museum Center, the Café do Castelo and the Casa do Leão restaurant are located today constitutes the most significant memory of the former medieval royal residence.

Also in the Romantic Garden area and on the terraces it is possible to see some architectural elements that were part of the former royal residence.

The illustration or reproduction of a 16th century drawing is the most expressive testimony of what the Paço Real and the city of Lisbon were like before the earthquake.

Due to its exceptional location, Castelo de S. Jorge stands out from all of Lisbon's viewpoints for the unique and majestic views it allows you to enjoy.
The Classification of São Jorge Castle in Lisbon
 
São Jorge Castle was classified as a National Monument by Decree of June 16, 1910.

This Monument underwent important restoration interventions in the 1940s and at the end of the 1990s, which had the merit of rehabilitating the monument, restoring its medieval design.

It is currently one of the most visited places by tourists in the city of Lisbon.