Hi, my 19yr old son has been invited to go to Amsterdam with a few friends. I suppose I'm worried about him getting mugged and so drunk he will end up in the canal. Does anyone have any idea about things/areas they should avoid. My son has only really started going out drinking this year so he'd not even used to that!!. Sorry if people think i'm being stupid writing this post but any help would be greatly welcomed. Sorry just an after thought is it an expensive place to visit?