Belém Tower (, ; literally: Bethlehem Tower), officially the Tower of Saint Vincent (), is a 16th-century fortification located in Lisbon, Portugal, which served as a point of embarkation and disembarkation for Portuguese explorers and as a ceremonial gateway to Lisbon. The tower symbolizes Portugal's maritime and colonial power in early modern Europe. It was built during the height of the Portuguese Renaissance and is a prominent example of the Portuguese Manueline style, but it also incorporates other architectural styles, such as the minarets, which are inspired by Moorish architecture. The structure was built from lioz limestone, a material local to the Lisbon region, and is composed of a bastion and a four-storey tower.
Since 1983, the tower has been a UNESCO World Heritage Site, along with the Jerónimos Monastery. It is often portrayed as a symbol of Europe's Age of Discoveries
History
thumb|left|The tower was classified as a UNESCO World Heritage Site in 1983 and included in the registry of the [[Seven Wonders of Portugal in 2007.]]
In the late 15th century, King John II had designed a defence system for the mouth of the Tagus that depended on the fortresses of Cascais and São Sebastião (or Torre Velha) in Caparica on the south side of the river. These fortresses did not completely protect the river's mouth, and further protection was required. the author Garcia de Resende affirmed the king's opinion that the defences of Lisbon were inadequate, and that he had insisted on building fortifications along the entrance to the River Tagus to supplement the existing defences. To this end, he ordered the "making of a strong fort", but died before any plans were drawn. King Manuel I of Portugal revisited the proposal twenty years later and ordered the construction of a military fortification on the northern margin of the Tagus at Belém. named "Master of the works of the Belém stronghold" by King Manuel, and in 1516 he began receiving 763 blocks and 504 stones for its construction, delivered by Diogo Rodrigues, treasurer for the project. As construction progressed, a man-of-war called the Grande Nau (Great Ship), a heavily armed, 1000–ton ship continued to guard the estuary at the mouth of the Tagus until the fort's completion.
The building was finished in 1519, just two years before Manuel's death, and Gaspar de Paiva was temporarily stationed to command the fortress; his commission was made permanent on 15 September 1521, when he was appointed the first Captain-General, or alcalde, and the fortress was named the Castle of St Vincent (Castelo de São Vicente de Belém), in honour of the patron saint of Lisbon.
In 1571, Francisco de Holanda advised the monarch that it was necessary to improve the coastal defences in order to protect the kingdom's capital. He suggested the construction of a "strong and impregnable" fort that could easily defend Lisbon and that the Belém Tower "should be strengthened, repaired and completed...that it has cost so much without being completed". D'Holanda designed an improved rectangular bastion with several turrets. In 1580, after a few hours of battle, the garrison stationed in the tower surrendered to Spanish forces under the command of the Duke of Alba. After this defeat, the dungeons of the tower served as a prison until 1830. The tower received military upgrades in 1589 and 1809–1814.
During the reign of Maria II, Almeida Garrett protested the site's degradation and under the persuasion of the Duke of Terceira, renovations were begun by military engineer António de Azevedo e Cunha. In 1999 the project received the Europa Nostra award for its restoration of the exterior. Although various guides have claimed that the tower was built in the middle of the Tagus, and now sits near the shore after the 1755 earthquake redirected the river, they are incorrect. The Portuguese Ministry of Culture and the Institute of Architectural Heritage indicate that the tower was constructed on a small island near the bank of the Tagus, opposite the shore of Restelo. As development extended the shoreline progressively, more and more of the northern bank crept southwards into the Tagus, the tower becoming integrated into the riverbank over time.
The Belém Tower was built from a beige-white limestone local to the Lisbon area and thereabouts called Lioz. The building is divided into two parts: the bastion and the four-story tower located on the north side of the bastion.
The 16th-century tower is considered one of the principal works of the Portuguese Late Gothic Manueline style. The decorative carved, twisted rope and elegant knots also point to Portugal's nautical history and are common elements of the Manueline style. The upper tier of the bastion is crowned by a small wall with bartizans in strategic places, decorated by rounded shields with the cross of the Order of Christ encircling the platform. King Manuel I was a member of the Order of Christ, thus the cross of the Order of Christ is used numerous times on the parapets.
While the tower is predominantly Manueline in style,
Interior
thumb|left|Interior casemate of the main bastion showing the cannon niches
thumb|left|A view from the second floor loggia
thumb|upright|Tourists visiting inside
The interior of the bastion, with a circular staircase at the north end, has two contiguous halls with vaulted ceilings supported by masonry arches, as well as four storage lockers and sanitary facilities. On the ground floor bunker, the floor is inclined towards the outside, while the ceilings are supported by masonry pilasters and vaulted spines. Gothic rib vaulting is evident in this casemate, the rooms of the tower and the cupolas of the watchtowers on the bastion terrace.
Two archways open to the main cloister in the north and south, while six broken arches stretch along the eastern and western parts of the cloister, interspersed with square pillars in the bastion interior, with gargoyle facets. The open cloister above the casemate, although decorative, was designed to dispel cannon smoke.