Answer: Porto and Vila Nova de Gaia
Some extra relevant information:
The Dom Luis I Bridge, an iconic symbol of Porto, Portugal, connects the cities of Porto and Vila Nova de Gaia. This magnificent double-deck iron bridge spans the Douro River and is one of the most famous landmarks in the region. It serves as a crucial transportation artery between the two cities, facilitating the movement of people and goods while also offering stunning panoramic views of the river and the cityscape. Whether you’re an architecture enthusiast or a visitor seeking breathtaking vistas, a walk across the Dom Luis I Bridge is an absolute must-do when exploring this beautiful region of Portugal.