The Catalonia History Museum is a definite must-visit in Barcelona. My knowledge of Catalonian history was at best sketchy. The museum filled the large gaps. It covers the prehistoric period right up to the present day. I loved it. We spent hours there.
The museum itself is next to the harbour and is in a converted warehouse.
The top floor is worth a visit as well. It has a terrace bar with great views over the marina. We popped in for a beer.