Murrawijinie Caves are a set of limestone caves located north of the Eyre Highway within Nullarbor National Park. You do require a permit for this place (I didn't get one) to be allowed to enter and 4WD is recommended from what I have seen.

The caves are accessed via an unsealed track and require a short walk to reach the openings. Inside, you’ll find large underground chambers typical of the Nullarbor’s extensive cave systems.

If you're into this sort of thing and have 4WD i'd say its worth having a look at but don't stress too much about going to this one.

What’s here:
✔ Limestone cave chambers
✔ Short bush walk access
✔ Remote, quiet setting
✔ Unique geological experience

Important notes:
✔ Permit required (check SA Parks before visiting)
✔ 4WD recommended for access track
✔ Bring torch/headlamp if entering caves
✔ No facilities
✔ Remote — travel prepared

This is best positioned as an optional adventure stop for travellers with extra time and the right vehicle. Not essential to the core Nullarbor crossing, but a memorable addition for those wanting to explore beyond the highway.