Admission to this site is included in your admission to the Castillo Serralles which is handy, because I probably wouldn't recommend it otherwise. The "gift shop" at the bottom is a ringer and, when we were there, wasn't open, rather, it was there for show. Making our way up the tower (stairs or elevator), we found that it is simply a high spot but offers little in different views than what we had just seen from the porch of Castillo Serralles. I had hoped for signage to point out different points of interest that could be seen but there were none - just windows. If you're already in the area, have a ticket, and have some time to kill, it's worth a stop, otherwise I'd say you can safely skip it.