The way we talk to each other in our social lives may be offensive culturaly. Even the way we sit. Stand. And greet eachother. These are all many types of barriers.
In terms of Gaelic Football and Hurling, there are a lot of things that are very strongly associated with the nationalist community in Ireland, that would go down well with the unionist community....
A culture and language barrier may make an individual avoid using a service as they may be foreign doctor and if a client cannot understand them they may feel stupid asking them to repeat there self.
The great barrier reef is a natural site, as humans did not influence the creation of it, but early Aborigional people and Torres Strait islanders had cultural connections with it.