Whilst all publicly accessible land is available with appropriate permission there are currently 5 locations in Western Australia where geocaching is restricted, with some locations entirely off limits.

It's always best to check for permission if you're unsure!

If you plan to place a cache in any of these locations:

• - Rottnest Island
• - Kings Park
• - Bold Park
• - City of Stirling
• - City of Melville

then make sure to visit the Groundspeak wiki to find the most up to date information on geocache placement restrictions in the above locations. 

If you're still in doubt, don't be afraid to contact your local reviewer. The reviewer for Western Australia is Balayang. You can find out contact information for Balayang here.