We recently booked 1 x one-bedroom and 2 x two-bedroomed Chalets at Coalmine Beach Holiday Park, near Walpole. I can comment only on a 2-bedroomed Chalet
that was very clean, modern and had several appliances that are not usually found in Cabins.
Our Chalet even had its own large BBQ, that was situated on the largest veranda that I have even seen in such accommodation --- even if it might be raining heavily, you would not get wet.
The Chalets are situated in a quiet section of the Park, and wildlife come to visit.
The Park is only a short drive from Walpole township.
I would recommend paying the extra $s for the Chalets (as opposed to the other Cabins) , especially for an extended stay.
The only negative was that the Chalets were booked through Agoda, who messed up our booking, and eventually overcharged us for our stay. (The staff at Coalmine Beach were eventually able to sort out the Agoda mess and they refunded the Agoda overcharge).
I would definitely recommend booking DIRECTLY through the Holiday Park. We would NEVER use Agoda again.
But a most enjoyable stay in very beautiful Chalets!

Just had 7 days in our caravan at this park that is surrounded by National park. We saw plenty of Blue Wrens & other birds, that hoped happily through the campsite. A kangaroo visited also, to the delight of those overseas visitors. Large private sites, clean ablutions and good facilities. Wifi available free at office.

Great campsite with plenty if space. clean amenities and cosy beach just around the corner. We stayed there in Feb - great sunny weather and not too many flies (they showed up only in the mornings). Great base to travel around (Walpole-Nornalup NP, William Bay NP etc.)