Many of the pre-Beeching lines cannot be re-opened, as they have been built over with roads and housing, especially in the South East. The closest you will get

Many of the pre-Beeching lines cannot be re-opened, as they have been built over with roads and housing, especially in the South East. The closest you will get to experiencing pre-Beeching railways is the Hogwarts Express in Florida, I'm afraid.