When I used to live there last year, I was most of the time skating this bowl.
But as Finknoos said, don't try it in the rain, or even if it is just a bit wet because of the canal close by.
Also, there is this nice d.i.y "ghetto-park", about 5mn in bike, from the bowl if you get bored.
http://goo.gl/maps/9VTyFAnd for the 'fun' part, check for Paradiso, Melkweg or OT 301. Always great bands playing there.
Or if you are into punk/hardcore/metal..., check 'occii' onAmstelveenseweg for cheap gigs.
I don't remember lots of places' name but have fun!