Note that those tourist busses are not all equal value. I don’t have a recommendation, but if you get a chance, check out the bus routes and frequency , and tour dialog, before you buy.
Also, for better or worse (no, just for worse), they are bus systems. When the shift ends, your driver wants to clock off at the depo. You get on at the end of the day, and he’ll run you express to finish on time.
Allegory with Venus and Cupid is where Terry Gilliam got the image of a foot that used to stomp on things in his animations for Monty Python’s Flying Circus.
As well as gruesome implements of old medicine, strange herbal remedies and suchlike, it also has one of the original operating ‘theatres’ - where students (and members of the public) could stand in the the tiers and watch operations in progress.
Good for an hour or two if you are visiting Southbank (home of Tate Modern, Globe theatre etc).
I was last there when I was 11, and was ABSOLUTELY THRILLED as only an 11 year old boy can be to ride in a DUCKW, a World War II era amphibious truck, the tour took in the cliffs from the sea. Unfortunately I did not care about the cliffs because I was an 11 year old boy in a vehicle that could drive right into the sea and float around.
If you do have a little time, the Isle of Wight is quite lovely. And if you have lots of time, Gerald Durrell’s zoo on the island of Jersey is a really good one, compasionate treatment of animalds as can be expected from the life-long animal lover.
I was fortunate enough to go there earlier this year as part of a work trip and it is brilliant. It also has all of the code breaking hardware that was used at Bletchley Park.
Lots of great things already suggested so I’ll just toss in a couple of tips.
London is vast and has enough to keep the average tourist going for months. So don’t worry about not finding something to do, there’ll be more than you have time for. Make plans for what you really want to do (be it shows, football, historic sites, museums, markets, galleries, food ..) and then see what fits into the gaps. If you take half the suggestions on this thread, you’ll end up having to rush through stuff so you can dash off and rush through more stuff.
Be careful with the long day trips. Oxford or Dover are probably OK, but Bath, Norwich or the Isle of Wight are a minimum two-and-a-half hours from central London, so unless you’re fine with 12+ hour days or want to spend half your day travelling, maybe best to pick one and plan to stay overnight. I certainly wouldn’t try and see Stonehenge and Bath in the same day.
My other tip is that London has one of, if not, the best food culture in the world. But that’s mostly because there are great options at every price range for almost every cuisine you could imagine. Understandably visitors want to try fish ‘n’ chips and other British food. And that’s fine but you need to find the good places. There is some bad British food in the super touristy areas, but there’s no excuse not to look up and find the good places of which there are many. And there are some fantastically high quality British restaurants as well that do unique dishes.
Indian food is obviously a staple of London cuisine. Brick Lane is the traditional place to find rows of Indian restaurants but they are all very average bar a few exceptions (usually off Brick Lane). There is also a decent Chinatown and quite a little Little Italy. Great Asian food is everywhere. If you want steak don’t go to the Angus Steakhouse but find a good one like Goodmans or Hawksmoor (who also do a fine British roast lunch).
To expand on various posters comments on cuisines, there are some fabulous food courts in London. The one I know best is Mercato Metropolitano (the Earls Court one.)
You wanna try Uzbek dumplings? Eat Argentinian? Modern Nigerian food? Really, you’re spoilt for choice.
Another thing to bear in mind is that, at least in the parts on London I know (south of the river) there are independent microbreweries everywhere, each with their own tap room. Or if you want to make a night of it, there’s the Beet Mile in Bermondsey. Here’s a useful looking summary of it.
Realistically, one or two “big” things from your must list per day. You’d be surprised how absorbing some things can be - and there are mealtimes and downtimes to be allowed for
I had 23 hours in London so I concentrated in one area - Greenwich. I did the Greenwich and Maritime museums and Cutty Sark. I took a boat from Canary Wharf to Westminster so saw a bunch of the sights near the Thames. I stopped at 221B Baker Street (not far from station) but it was after the museum closed.
Not so much a trip out, but rather something to look out for if you’re chilling around town: there’s a lot of street art in London. Shoreditch is notorious for it - you can do a Shoreditch street art tour if you’re so inclined.