We transited through London this past November for a total of only 2 days so I don’t have much intel for you. Big Ben is completely enveloped by scaffolding at the moment (not sure when that is coming down) so that was a bit disappointing for our 5-year old spring onion. Within walking distance of Knightsbridge, I think, is Star Tavern where we had a decent pub lunch, but nothing earth-shattering. Spring onion enjoyed looking at all the embassy flags as we walked there and onto the Science/Natural History Museums.
Looking forward to hearing about your trip!
Here’s a relevant-ish thread. And my trip report.
