What's going on here?

This morning I had a little trek along the lane and just look what has popped up in the cow field. …......................A giant tent, holiday home, party venue, bubble, structure??? Yesterday at 8am there were a lot of men in the field erecting scaffolding and churning up the grass we wondered what was going on.



So now we know..........................…..................Except we don't?!



What is this? Why is it here? What is it for? Is it permanent/temporary? Where are the cows?



Sometimes life is a mystery and no one knows the answers???

PS - Don't often post photos in 'extras' but wanted a record of this.  Can people really erect 'structures' this size in fields that are normally occupied by animals? (There's some portaloos there too).

PPS - Whatever it is; it's got lovely views!!!