The
Wungong Gorge Walk is one of the prettiest walks in the Perth Hills. Meandering through groves of trees and rocky outcrops, and alongside a winding stream, it's a great walk for almost any time of year (some parts may become inaccessible if there's been a lot of rain.)
It's a beautiful valley, and the walk itself begins in Bungendore National Park (near Wungong Dam), and ends on the Southwest Highway. There are a number of shortened walks available, ranging from easy to difficult.
Beneath the high walls of Wungong Dam is a great little picnic spot, complete with all the amenities you'll need for a great day. The dam itself is an interesting, and somewhat spectacular (depending on how full it is) sight. The picnic area is beneath a beautiful grove of trees - so there's plenty of shade if the day is hot.
As can be expected in the bush, there is a range of native flora and fauna to be seen: magpies, eagles, galahs, kangaroos and, at the right time of year, wildflowers (among many others.)
Overall, I highly recommend this area if you want to escape into the outdoors without going too far from the city - the Wungong/Bungendore area is located about ten minutes drive from the Armadale Shopping Centre.