San Carlos is classified here as a B&B. I would, however, upgrade it to a 2 or 3 star hotel. The hotel itself is comfortable. There is parking available in the back of the hotel. The furniture in the rooms is old but relatively well kept. Rooms and bathrooms are clean.
Across the street from the hotel there is a little cozy restaurant that is really worth the visit (very cheap all-you-can-eat lunch buffet).
The hotel is located on a small hill, so higher floors have a beautiful view of the city. Walking to the city center is easy and should take you 5 to 10 minutes.
In the city center there is a big Tramontina store (it is their factory retail, so you will find most Tramontina products -kitchen and gardening tools mostly- at discounted prices).
Close to the Tramontina store, you will find the site of the Festiqueijo fair, held every year in July. It is probably the biggest reason to go to Carlos Barbosa if you are not a compulsive Tramontina... More