London. Book a tour at Fullers. There are so many great pubs. Favorites are The Dove, Market Porter, The Grapes, Holly Bush, Royal Oak, and on and on. Hit the museums if you haven’t been, many are free. London is easy to get around, so don't think something is too far. We done many tours by London Walks, choose a topic and try one.
Berlin has great museums too, primarily on Museum Island. Only been twice. Last time we were near The Castle bar which had a good selection. Many small bars to explore. I didn’t realize we were near the Scheeeule brewery until later, they're doing some great Berliner Wießbier. Had a fun evening at Georgebraeu on the River Spee. So much more to do not beer related. We did an English walking tour on our first visit 20 years ago.
Do some internet searches for what you want in each city. I'm doing to same for the fall.