Pretty purple weed?

Growing like a weed, coming up from under the fence, but so pretty! Any ideas?

 

Is it a campanula?

 

Yes, looks like Campanula of some sort

 

It looks like a Campanula Pyramidalis (Chimney Bellflower). Can you look over the fence and see how it's growing? They're bushy perennials, outdoors growing about 3/4' high but it is possible to grow them in pots in a greenhouse etc where they can get upto about 8' high and covered with flowers.

 

It is an empty patio on the other side of the fence in both spots I have now found it in!

 

So, someone had tried to murdered it and hide the evidence under the patio, eh?