How many favourite places can you have? I don’t know but there a definitely many places that I like and the castle of Montemor-o-Velho is one of them. I’ve been there more than once, enjoyed a stroll along the well maintained walls, visiting the nice but relatively simple chapel, the ruins and the wonderful view over the (rice) fields, the Mondego, the sea in distance to the West and a nature reserve to the North.
Some times I’ve been the only visitor, sometimes it was quite busy as it seems to be a popular wedding location which I can understand. At the castle grounds is/was also a café which I remember to be open and closed at other times. It’s been a few years since I’ve been there the last time and things might have changed. Back then there was free entrance and you could either drive and park almost in front of the main gate or walk up from the little town.
The town of Montemor-o-Velho is not that impressive compared to some well-known tourist hot spots but worth-while a little stroll with some nice cafés and older houses. A couple of times a year the city becomes very busy with big fairs on its festival grounds near the river Mondego.