The Bridge of Ajuda (Portuguese: Ponte de Nossa Senhora da Ajuda, Spanish: Puente de Nuestra Señora de Ayuda) is a dilapidated bridge that crosses the Guadiana River between Elvas and Olivenza.

The bridge was constructed between 1520 and 1521, during the reign of King D. Manuel I of Portugal from the left bank of the Guadiana, in the parish of Senhora da Ajuda, along a roadway segment between Elvas and Olivença (and attributed to the "Arruda brothers").^[1] During 1597, many of the archways were damaged or destroyed during flooding.^[1]

Between 1640 and 1642, Matias de Albuquerque, Governor of the Alentejo, began the refortification of Olivença with the construction of a third or fourth lines of walls.^[1] During this period it is possible that the bridge was rebuilt, since it was in a state of ruin at the time of the Governor's visit to Elvas and Olivença.^[1][2] However, it was partially destroyed by Spanish forces in 1657. It was then rebuilt in the same century.^[1]

In 1705, redoubts were constructed to reinforce the bridge over the Guadiana, designed by Manuel da Maia.^[1] In 1709 the bridge was partially demolished by artillery during the War of the Spanish Succession.^[1]

The Spanish army, under the command of D. Manuel Godoy annexed the town of Olivença in 1801.^[1]

In 1903, in Vila Viçosa, King D. Carlos proposed the reconstruction of the bridge.^[1]

On 24 January 1967 the Portuguese government declared the bridge a Imóvel de Interesse Público (Property of Public Interest).^[1] This was complimented, on 13 March 2009, when the Spanish government declared the bridge as a Bien de Interés Cultural (Possession of Cultural Interest).^[3]

The bridge is located in a rural environment, isolated and encircled by wild vegetation, approximately 100 metres (330 ft) from the Chapel of Nossa Senhora da Ajuda, along a segment of abandoned road 12 kilometres (7.5 mi) between Elvas and Olivenza.^[1] Although in ruin, the bridge was 453 metres (1,486 ft) long and 5 metres (16 ft) wide, with a platform that was at most 161 metres (528 ft) above the river.^[1]

Eight arches remain along the right margin and 5 along the left margin, consisting of inconsistent rounded arches supported by talhamares.^[1] The archivolts, with two rows of staves, are supported by quadrangular pillars reinforced by high talhamares.^[1] Along the main platform, an old tower was erected along the sixth arch of the right bank, which was constructed over large boulders, now visible along the margin.^[1]

• Guadiana International Bridge
• Lower Guadiana International bridge