Hi Denise! Great question. Your hunch about Sines is correct – it does have a cute historic town centre and castle (I love to stop at Adega de Sines for lunch), but it is a strong industrial city with a mega port. In a sense that makes it more of an authentic local and not touristy town! The beaches north and south of Sines are incredible. My feeling is that you’ll enjoy Porto Covo or Vila Nova de Milfontes, both south. Porto Covo is a small village with a charming central square and lots of pretty beaches and coves to explore. I’ll try to write a guide on it soon. VNdMilfontes is a larger town with a coastal holiday feel – very relaxed with a handful of stores, old fort etc. It’s set where the river meets the ocean and offers a bit more to do. Otherwise I’d suggest staying at a rural property that takes your fancy and explore from there. Hope that helps!
Daniela