Porto is the second-largest city in Portugal. Porto's history dates back to the IV century, when Romans invaded the Iberian Peninsula, although Proto-Celtic ruins were discovered in different areas of the city. The historic centre is considered to be a World Heritage Site by the UNESCO and it is one of the most visited attractions in Porto. You can find several shopping streets, squares and historical buildings that reflect the origins of the city, such as the Cathedral. Foz is a highly-tourist area, considered one of the most beautiful regions in Porto, where you can enjoy the beauty of the Atlantic Ocean while you go for a romantic walk. Do not forget to go through the city and gaze at all the attractions visitors have to see in Porto!