Using fictional places within real places in Fiction?

Hi all

Just wondering has anyone invented a town or city within a real country/city/region, and what the benefits/downsides are?

Basically my story is a crime story (organised crime, drug dealing etc...) set in Dublin, but I'm not sure where in Dublin it should be set, so I'm considering using my own fake suburb/town within Dublin.

The reasons for this being that I'm not sure I could accurately and convincingly describe the real places themselves, and it may seem lame and unconvincing to those who know these areas. Basically I think it would give me more scope and be easier for me to use my own fictional town/area, but do you think this could detract from the realism? Like someone from Dublin reading it thinking 'where the hell is that?'

Thanks for any responses