This was definitely also a 'thing' when I was growing up in Somerset, I think they just called it a 'garden open day' or similar, but I can distinctly remember

This was definitely also a 'thing' when I was growing up in Somerset, I think they just called it a 'garden open day' or similar, but I can distinctly remember wandering around one massive garden and nearly walking straight into the pond covered in Duckweed.