Occupying a strategic, hilltop position overlooking the Sado River is the castle of Alcácer do Sal. The hilltop has been settled since prehistoric times, but today it is an Islamic fortress that dominates the hill; a fortress that played a part in the struggles between Muslims and Christians for Portugal. Besides the castle and Roman points of interest, the historic convent is now a luxury hotel, the Pousada de Alcácer do Sal.

The Alcácer do Sal Castle overlooking the Sabo River.

The Islamic fortress occupies a strategic position above the Sabo River. Photograph © Wikimedia/Joaomartinho63

Standing over the river valley on a hilltop consistently occupied since the Roman presence, the city became an important urban and military centre of the Muslim rule in the Iberian Peninsula when its economic prosperity made a strong fortification necessary. Originally an early 12th century castle but extensively rebuilt by the Almohads between 1191 and 1217, it rises at a height of sixty meters above sea level, with an approximately elliptical design, reaching an extension of 260 meters large.

The battlements and parapet of the Alcácer do Sal Castle.

Visitors to Alcácer do Sal can walk along the castle parapet. Photograph © Wikimedia/Vitor Oliveira

Main Facts & Features

Alcácer do Sal is from the Arabic word al-Kasr, meaning fortress, and the Latin Salatia, meaning ‘city of salt’.
Period Almohad
Architectural Features Roman ramparts and towers
Size 8 hectares

One of the square towers at Alcácer do Sal Castle, Portugal.

The gardens of the hotel back on to the castle walls. Photograph © Wikimedia/Elisete Reis

Timeline: A Brief History of Alcácer do Sal Castle

2nd/1st Millennium BC Occupation of the site starts in prehistory, with evidence of Iron Age communities using the hilltop. But human occupation of the general area begins further back in the Stone Age.
1st Century BC Romans occupy the region. As a result of trade in salt the town becomes wealthy enough for locals to mint their own coins – bearing the inscription Imperatoria Salacia.
5th-6th Century AD Visigoths take over the Roman town and construct a simple basilica.
715 AD Muslim conquer Salacia (renamed Al-Kasr) and the city’s first defences are built soon after, or in the the early 800s.
844 and 966 AD Viking fleets sail up the Sado River and attemptd to take the Castle of Alcácer do Sal – without success.
1160 The city is first captured by Portugal’s King Afonso Henriques during a night raid.
1191 The Almohads retake the castle and set about enlarging and reinforcing the castle, by adding ‘albarrana’ towers and using the taipa technique of constructing walls. These mirror other Islamic structures such as those in Badajoz and Sevilla.
1217 During the reign of King D. Alfonso II, the castle is finally taken by Portuguese Christians headed by the Bishop of Lisbon, Soeiro Viegas, with the support of English, German, Flemish and Danish Crusaders. King Afonso II donates the castle to the Knights of Santiago.
1289 The castle and its fortifications are rebuilt in the context of rebuilding defences nationwide.
30 October 1500 King Manuel I marries Maria of Castilla, daughter of the Catholic Monarchs of Spain, at the castle.
1573 As a result of its decreasing military significance, a nobleman by the name of Rui Salema establishes the Nossa Senhora de Aracaeli Convent inside fortress. This continues for some 300 years until the dissolution of the monasteries.
1755 Following the Lisbon Earthquake, the castle suffers substantial damage: towers and parts of the wall collapse.
23 June 1910 Classified as a National Monument.
1969 Following another earthquake, and further damage to the castle major restoration works at the castle begin and continue into the 1980s.
1990 Restoration work to turn the convent into a hotel is stopped when remains of a Roman forum are discovered. The hotel opens in 1998.

What is there to See at Alcácer do Sal Castle

The fortress has a mix of stone and taipa material. Originally there were 30 towers, the highest of which known as the Algique Tower was about 25 metres high. The keep would have been bigger than it is today, an elliptical shape with maximum dimensions of 260 meters by 150 meters. There were two main entrances, one to the northeast, the Porta Nova, and the other to the east, the Porta do Ferro.

A smaller barbican surrounded the main walls (of which some remains have survived) and the remnants of a wooden palisade can be seen in places on the hill slope.

On the northwest wall, next to the old gate, are the buildings that made up the Convent of Aracaeli (double choir church, cloister and monk cells), built in the late 16th century. In the 1990s substantial but sensitive refurbishment of the cloister were carried out to create a reasonably high-end, the Pousada de Alcácer do Sal.

In front of the Church of Santa Maria do Castelo are the recently excavated remains of a part of the Roman Forum.

Beneath the hotel is the Castle Archaeological Crypt. Found during excavations required for the refurbishment of the convent, here you will see the remnants of some 2,700 years of human occupation on the hill. Medieval walls from both the Christian and Islamic occupation of the castle are built on top of Roman walls, which are in turn above Iron Age walls dating to the 7th century BC.

The Church of Santa Maria do Castelo within the bailey of Álcacer do Sal Castle.

The church within the bailey of Castelo Álcacer do Sal. Photograph © Wikimedia/Xuaxo

Where is Alcácer do Sal Castle?

Alcácer do Sal is 90km southeast from Lisbon, in the north west of Alentejo, and south of the Setúbal Peninsula. It lies next to the Sado River delta, with the municipalities of Palmela and Montemor-o-Novo and Setúbal to the west.

Visiting Alcácer do Sal Castle

Getting to the castle

Bus: Expresso from Lisbon, Coimbra, Faro, Beja and Évora.
Train: CP – Comboios de Portugal, train from Lisbon to Setúbal and from Setúbal to Ermidas do Sado, stopping at Alcácer do Sol.
Cars: highway A2 from Lisbon crosses the Sado river right next to Alcácer. A1 highway for people coming from the north.
Tourist bus: Sightseeing Yellow Tours from Carristur. Departures every 30 minutes from Lisbon, Évora, Setúbal and Palmela.
Lisbon International Airport is only 90kms from the town, at which you could hire a car.

Opening Hours

The castle area, including the uncovered remains of the Roman Forum, is accessible daily and free to enter.

The Archaeological Crypt is open every day except Christmas day, New Year’s and May 1.
July to August: 9h30 – 13h00 and 15h00 – 18h30
Rest of the year: 9h00 – 12h30 and 14h00 – 17h30

Municipal website for the Castle, the Archaeological Crypt, and the Roman Forum.

Good To Know Before You Go

Visit the Sado River estuary and look out for dolphins.

Less than 30 km away, you will find one of the most closely guarded secrets of the dazzling Portuguese coast: the Comporta, Carvalhal and Pego beaches.

More Things to See at Alcácer do Sal

Church of Senhor dos Martires: One of the oldest Christian temples in Portugal, known for the mysterious symbols engraved on its walls and for its various chapels.

Misericórdia Church: According to an inscription on one of the portals, this church was consecrated in 1547. The interior walls are decorated with stucco and azulejos from the 1600s.

Church of Saint António: Founded in 1524, this is a classic style church with a remarkable Renaissance dome.

Strolling through the streets of the old city is the best way to discover the most charming and historical areas of Alcácer do Sal. Through its small streets and numerous stairs leading to the castle you get spectacular and interesting views, up and down.

Municipal Museum of Archaeology houses artefacts from the region, from prehistory into Medieval times.

Stay in the Alcácer do Sal Castle

Have a look at the wonderful collection of photos in the gallery and book a stay on Booking.com

The courtyard of the Pousada de Alcácer do Sal, Portugal.

The renovated cloister of the convent is now part of the four-star hotel, Pousada de Alcácer do Sal. Photograph © Wikimedia/Elisete Reis