Salmon fishing, surfing, whale-watching and wildflowers are all found in the Walpole-Nornalup National Park along the south coast of WA. It has stunning beaches and just as stunning forests.
Rare eucalypts are found here and some of the super tall trees can be explored at ground level or on the sky-walk trip amongst the trees above ground. There are camp sites and hostels and so much natural beauty to see in this park.
Yanchep National Park
For a family friendly and close to Perth location, it's hard to beat the Yanchep National Park. During the school holidays, rangers even present a variety of activities such as caving and koala watching just for kids. There are wetlands and bush areas where walkers can hopefully see kangaroos, possums and bandicoots. Boats are for hire for paddling on the lake, there are picnic and barbeque areas and it's all within an easy drive of Perth.