I was out in Madrid 2nd to 7th Jan with the in laws. We went for a walk along the new 8km long park they have created by the river Manzanares. It's 10 mins from where they live and it used to be the motorway, but they put that in a tunnel in preparation for the 2012 Olympics they lost! Anyway, it's a very nice park with cycle/skate paths inter-twined and loads of things for kids to play on. I'll run it a few times when I'm over there next.
At the start of the park I found this, and just had to take some pics for you lot:
It looks like a pro track to me? It was all fenced off too so I expect it is used only for events ot pay to ride.
I have an old universal stingray BMX in the mountain village 2hrs drive away, but I'm now tempted to take over somethibg track orientated.