Palmela Castle has ruins you can walk through, museum displays, and a (deconsecrated) church that you can visit for free. There are lots of opportunities for photo ops, with cutouts of historic figures to pose with. There seemed to be more displays that weren't open when I visited. There are free bathrooms near the cafe, along with sporadic wifi.
There are also a few small shops, a cafe, a restaurant, and a hotel.
I was there on a drizzly day, so maybe I just got lucky, but it was an unusually pleasant tourist experience. Usually castles are mobbed with people, so it was a real treat to be able to enjoy the views and nerd out over artifacts without tour groups and shrieking children. The view of Setubal and the countryside is lovely. read more