An Australian couple with some deep-seated relationship issues go camping in the "bush" or whatever the fuck they call it there. In the process, they manage to disrespect Mother Nature by littering, hitting animals with their car, etc. So the outback bites back, the animals all go apeshit on the couple (no actual apes though).
Picnic at Hanging Rock is already something of a horror movie, but that said, Long Weekend is kind of a more generic horror movie version of similar ideas, mining horror from the fathomless mystery of the Australian outback. The couple (and I hate to say it, especially the bitchy woman) are kind of tough to spend so much time with and I'm not so sure you like them enough to fear for their safety, but Long Weekend is offbeat enough that it deserves maybe a cursory glance.