Throwing something fun into the list if anyone's looking for something unique... we had a full day in London before we went to Liverpool for a cruise to Norway, so since my (extended in-law) family members had never been, I did the usual "cram as much London into one day" death march as we could, but we ended up (pre-made reservations, of course) having dinner at the top of the "Walkie Talkie" building, up at the 35th/36th floors - known as the Sky Garden. There are several restaurants up there (again, you need reservations). We dined in the Darwin Brasserie (https://skygarden.london/restaurants/darwin-brasserie/).
The food was really nice - pricey, but worth it.
The views, though, were fantastic... you had a great sunset view looking west over the city, and were situated directly overlooking the Tower of London and Tower Bridge.
...and after dinner (we timed it obviously for sunset!), the views of the lit-up Tower Bridge were really stunning: