This is utter balls. The South Bank was not no go in the 1980s. And though there were then - and before then and since then - parts of London that were dodgy and best avoided late at night, this is true of every major city.
George is so right. Also, 30 years there were areas in London, such as Southbank and many others, that were no-go. Nowadays, the misinformation about London is beyond belief. London is v expensive, yes, but the best and greatest big city in the world, by far. And I travel…a lot!