Looking the other way across the river from Porto to Vila Nova de Gaia. Vila Nova de Gaia, or simply Gaia, is a city in Portugal. It is located in the Porto district, south of the city of Porto on the other side of the river Douro. The city proper has a population of 178,255 and the municipality contains 24 parishes with a total population of 288,749 inhabitants, being the most populated municipality in Norte region. Gaia together with Porto and other 12 municipalities makes up the commonly designated Porto Metropolitan Area. It is also well known for its lodges (locally known as caves) where the world famous Port wine is stored and aged. The lodges have become a major tourist attraction.