Can anyone identify this herb?

[TheCountessofFitzdotterel]

It smells lovely. I want some.
It is in the historical gardens of my local folk museum and smells like something you might strew on the floor.
Thanks

Vague recollection this is tansy.

If it is, it spreads like nobody's business- used to spot and dig out loads when a volunteer gardener

Yes! I think you're right, thank you.
It was all over the place so that definitely fits re spreading.
It's excellent news for me too as I already have some tansy seed.