Out of curiosity I looked at geograph, an interesting website in it's own right & also a copyright free source for adding things to OSM (whereas Google Maps is forbidden( Bing Streetview is ok btw))

https://www.geograph.org.uk/photo/3410344

This is what the Rock Garden looked like  on 13 April, 2013, and I do believe there's a Cymru translation on the sign if you're interested in adding that...