Being the second biggest city in Portugal, Porto is located in the northern part of the country, and is settled on the Douro river estuary. It is one of the oldest European cities, and is listed as a World Heritage Site. The city itself isn't actually that populated with only some 300,000 inhabitants. But the greater metropolitan area paints a very different picture with over 2.5 million people. The outer metro area also takes in cities such as Maia, Gondomar, Gaia and Matosinhos.
In the 300's AD when the Romans occupied the area they called it Portus Calle.
Even though the city has a semi Mediterranean climate, it enjoys much cooler temperatures than other areas with the same climate, due to beautiful breezes from the Atlantic Ocean. It can still however experience spikes of 40 degrees Celsius in summer, and very infrequent temperatures of below 0 degrees Celsius in winter.
The architecture of the city is somewhat varied, with old world right next door to modern. But it is definitely a place to take the most comfortable walking shoes that you own. Most of the buildings are actually built into the cliffs that face the ocean. It is extremely hilly, and there are carved stone stairs that wind all up and down the cliffs. But rest assured, that making the effort to walk up is well reward with beautiful and picturesque views of the city and ocean.
Over all the people of Porto are friendly, but they can be commonly misunderstood for being rude, but this is only due to the fact that they are a very literal and direct race of people. A good example of this is if you go to a pub and ask them if they have a food menu. The answer more than likely will be a no, with no more dialogue entered into. If you wish to quiz them further, you will find out that they don't actually serve food, hence their response whilst very short is not in fact rude, just direct.
If you can speak Spanish you will on the whole get by pretty well in Porto. The locals will understand the vast majority of what you are saying, but sometimes the oldies can get a bit thingy and remind you that you're in Portugal, so speak Portuguese.
There are a multitude of sights to take in whilst in Porto, make sure you have the following on your list. The Porto Cathedral, Igreja de Santa Clara, Serralves, the Church of Sao Francisco, the Clerigos Church, Palacio da Bolsa, the Dom Luis Bridge, Sea Life Porto, Coliseu do Porto, the Rivoli Theatre, Palacio de Sao Joao Novo, the Church of Sao Martinho Cedofeita, the Episcopal Palace of Porto, the Church of Saint Ildefonso, the Maria Pia Bridge, Casa de Serralves, the Lapa Church, Ingreja de Sao Bento da Vitoria, the Meseu Militar do Porto and Casa Museu Guerra Junquiero.