It's a lacecap Hydrangea, many different forms available, often hard to tell apart. This looks like a nice one, by the way.

Great. I saw it a local stately home but didn't know its name. Thank you.

This is one of the few Hydrangeas I actually like. Such a beautiful colour.

Yes! Looked at this question last night but being a newbe thought would wait to see if got it right. I'm getting better :-).