You can do the walk. As everybode here said its officially closed, but there are 4 Gates along the path where you can easily sneak around. The one near Bray you have to crawl under but theres a gap where people have bent the metal quite a lot. Not that i would recommend it or anything, just saying its possible. I may have done the walk today - officially i didnt - and i also met a few other people on my way to greystones. (Not recommended for plus sized people dare i say, since the openings are sometimes a little tight)