The city

Vila Nova de Gaia: It is located south of the city of Porto on the other side of the Douro River. The city proper had a population of 178,255 in 2001.[1] The municipality has a total population of 302,295 inhabitants (2011),[3] making it the most populous municipality in Norte Region. Gaia along with Porto and 12 other municipalities make up the commonly designated Porto Metropolitan Area.

The city contains many cellars (locally known as "caves") where port wine is stored and aged. These cellars have become a major tourist attraction.

Oporto: Located along the Douro River estuary in northern Portugal, Porto is one of the oldest European centres, and its core was proclaimed a World Heritage Site by UNESCO in 1996, as "Historic Centre of Porto, Luiz I Bridge and Monastery of Serra do Pilar". The historic area is also a National Monument of Portugal. The western part of its urban area extends to the coastline of the Atlantic Ocean. Its settlement dates back many centuries, when it was an outpost of the Roman Empire. Its combined Celtic-Latin name, Portus Cale, has been referred to as the origin of the name Portugal, based on transliteration and oral evolution from Latin. In Portuguese, the name of the city includes a definite article: o Porto ("the port" or "the harbor"), which is where its sometimes used English name "Oporto" comes from. 

Among the architectural highlights of the city, Oporto Cathedral is the oldest surviving structure, together with the small romanesque Church of Cedofeita, the gothic Igreja de São Francisco (Church of Saint Francis), the remnants of the city walls and a few 15th-century houses. The baroque style is well represented in the city in the elaborate gilt work interior decoration of the churches of St. Francis (São Francisco) and St. Claire (Santa Clara), the church of the Clerics (Clérigos). The neoclassicism and romanticism of the 19th and 20th centuries also added interesting monuments to the landscape of the city, like the magnificent Stock Exchange Palace (Palácio da Bolsa), the Hospital of Saint Anthony, the Municipality, the buildings in the Liberdade Square and the Avenida dos Aliados, the tile-adorned São Bento railway station and the gardens of the Crystal Palace (Palácio de Cristal). A guided visit to the Palácio da Bolsa, and in particular, the Arab Room is a major tourist attraction.