Dona G
Google
One of the major things to do (aside from going to the beach of course!) for those in Sitges. Their selection of art is pretty good, and there is also an app for Sitges Museums that gives self-guided audio tours through some of the exhibitions that I highly recommend.
The museum complex does take student discounts, for those who are curious about that.
To enter the house/palace, you have to pay for the guided tour, which lasts 50 minutes. I believe the English one is offered at 11 am, and the Castilian one at 1 pm. It has a stunning view of the ocean that in and of itself makes the tour worth it.
For those who can't make the tour through the palace, I would still recommend the museums.