Oil leak question???

I have a 96 golf and i'm leaking oil from in between the oil cooler and oil filter base. I know a nut holds the oil cooler on the base but i'm just wondering if there is a gasket between the two that i need to replace, or do i just need to tighten the nut?? Or is there a seal that is inside between the 2 that is shot???

Jip there is a gasket but they normaly dont give problems and don't overtighten the nut you will end up damaging the cooler but take it off and see what it looks like.

I cant seem to get anything up there, what's the best way to get to the nut at the end of the oil cooler???

I Used a long shaft socket to take mine off.