My previous experiences with the La Rierada area consisted of being attacked by wild dogs, so it was nice to return here with a more positive experience.
Can Castellvi is a masia-style country restaurant (do you want meat with a side of meat?). The big attraction is the farm, where you can send off the kids with a monitor (for 10 euros or so, depending on the group size) while you enjoy some adult time.
The kids absolutely loved the farm. They eat quickly upstairs and then head off to the farm for two hours while the food came (very slowly... I was starved by the time my big hunk of red meat arrived), but they timed it pretty well so that the deserts and coffee were being served when the kids came back.