The Historic Centre of Oporto, Luiz I Bridge and Monastery of Serra do Pilar is a UNESCO World Heritage site on the hillsides above the mouth of the Douro, in Porto and Vila Nova de Gaia, inscribed in 1996. UNESCO describes it as an urban landscape with a 2,000-year history, named Portus, or port, by the Romans in the 1st century BC.
The site covers 51 hectares: 49 in Porto, 0.5 for the bridge and 1.5 for the monastery in Gaia, with a buffer zone of 84 hectares in Porto.

Monuments in the Historic Centre of Porto
- Porto Cathedral: the cathedral on the hill of the Sé, with a Romanesque choir, built and enlarged from the 12th century.
- Church of São Francisco: a Gothic church with an interior lined in gilded carved wood, the only part of the São Francisco convent left after the fire of 1832.
- Palácio da Bolsa: the neoclassical seat of the Porto Commercial Association, built from 1842 on the ruins of the São Francisco convent.
- Clérigos Church and Tower: a Baroque church and bell tower by the Italian architect Nicolau Nasoni, whose tower rises above the city centre.
- Church of Santa Clara: a convent church that UNESCO cites for its Manueline style.
- São Bento Station: the railway station of the city centre, one of the later buildings UNESCO lists within the site.
- Luís I Bridge: the two-deck iron bridge between Porto and Gaia, built from 21 November 1881 and opened on 31 October 1886.
- Monastery of Serra do Pilar: a former monastery in Vila Nova de Gaia above the bridge, with a circular church and a circular cloister, classified as a National Monument in 1910.
- Ribeira: the riverside quarter at the foot of the historic centre, facing the Port wine cellars of Gaia.

History of the Historic Centre of Porto
- 1st century BC: the Romans name the settlement at the mouth of the Douro Portus.
- From the 12th century: the cathedral is built on the hill of the Sé, the oldest part of the city.
- 1881 to 1886: the Luís I Bridge is built, and its use carries a toll until 1944.
- December 1996: UNESCO inscribes the Historic Centre of Oporto on the World Heritage List under criterion (iv). The name of the site later adds the Luiz I Bridge and the Monastery of Serra do Pilar.
Visiting the Historic Centre of Porto
- Parish: most of the historic centre lies in the parish of Cedofeita, Santo Ildefonso, Sé, Miragaia, São Nicolau e Vitória.
- Crossing the river: the upper deck of the Luís I Bridge carries a metro line and pedestrians, and the lower deck links the Ribeira with the Gaia riverfront.
- On foot: the historic centre is built on steep slopes, with stairs and narrow streets between the upper town and the river.
Places to visit in Porto
Porto, Portugal
Historic Centre of Oporto, Luiz I Bridge and Serra do Pilar
Palácio da Bolsa
Livraria Lello
Foz do Douro
Clérigos Church and Tower
Church of São Francisco
São Bento Station
Porto Cathedral