To go to Dublin

To be in Dublin or to go to Dublin(originally used in German) describes a person being high. It finds it's origin in Dublin, when a few Austrian Students met a drug dealer and stoner, who offered them "chocolate caramel", which was a specific type of drug.
The joint itself is called "ticket to Dublin"

Julian: Man Id love to go to Dublin today, you joinin me?
Jonas: Sure, ill get the tickets and we're gonna have much fun!