When my friend and I, distracted by the beauty of the Douro valley, noticed we had no hotel reservations for that night, it was almost too late, most hotels right by the Douro were fully booked. Fortunately, we could still find a room in the Hotel Aguiar da Pena, although we were a little concerned by the distance to Peso da Regua, where most tourists prefer to stay. It was already dark, but the road was EXCELLENT, so we got there much earlier than we had expected.
We were really surprised to see such a big hotel in such a small town. The hotel was amazing and very very affordable, we couldn't have found a better place to stay. There was a huge restaurant, the staff was very nice, the room was clean and comfortable, they even had an outdoor pool. Next day we drove a little bit around Vila Pouca de Aguiar (what a lovely name!) and were once again surprised to see such a little gem, which among pother attractions had a ruined castle.
So I highly recommend this hotel if you're visiting the Douro region. It's a great and affordable place to stay, and not far from the action.