The apartment that we live in, here in Basel, has a childrens playground to the side of it. Every evening, the kids are enjoying themselves on the play equipment - no problems.

There is also an area which has been used as a football pitch since the playground was first installed (about 18 months). The ball gets kicked against the windows of the (empty) ground floor office and a wall which borders the gardens of the apartments. To retrieve the ball when it gets kicked over the wall, the kids climb over a gate or over a (now ruined) chain-link fence. It's not a major problem - kids will be kids and I'd have done the same sort of thing when I was young.

The problem we have is that the football is going on until 10pm at night, almost every night including weekends.

Now, I'm not usually a moaning old git, but 10pm is just crazy. It's bloody annoying to hear the scittering noise of the ball on the tarmac and crash of the ball hitting the wall along with the kids shouting. We live a few apartments along but there are some the are directly above the area and it must drive them mad. The kids are school age and I can't understand why their parents would allow them out so late ??

Normally, I would go down and tell them to sod off after 9pm, but my German isn't good enough. So who should I approach to get this sorted out ?