During our time in Santiago, we stayed at the Campground As Cancelas. When you are coming to this campground, I would recommend you first to park outside and have a walk around to see where your caravan would fit. Many spots are tiny and tight. If you have a huge caravan there are only a few spots which might suit you. The campground is relatively small, and you need to drive up a steep hill to get to the places.
The toilets and showers are like on many other campgrounds, pretty old and hard to regulate. Either very cold or very hot. The toilets, however, have toilet paper in each cubicle, so that is nice. No soap of course.
For the kids, there is a little playground and a small area where you can play ball games. There is a pool, but it is not for small kids.
The best with the camping site is that it is walking distance to the city and you have a shopping mall only 60 meters away. Here you have a big supermarket, a food court, a little playground and many other shops offering distraction.