A seven-hour stopover gives you just enough time to whizz out of Heathrow, see one thing, and return.
Buckminster Palace? The British Museum?
I went to have tea with Rav and Mrs. Baddiel.
They are most extraordinary people... the number one tourist attraction in London, in my book.
Rav Baddiel is much amused that a lecture of his has been put up on YouTube:
It is in English, despite the German title (he gave it in Berlin). Do check it out.