The current 'Another Energy' exhibition of female artists is excellent and well worth a visit.
Be aware that (contrary to information in my travel guide) entry for the City View is not included in gallery entry. The hordes of staff were not able to answer my question in English when I arrived on whether it was possible to buy a ticket for both, and I ended up just getting a ticket for the exhibition. As I enjoyed this I didn't particularly mind, but clarity would be welcome. And there are way too many helpful people shepherding you around the building!