Melbourne

It's much nicer in summer. Don't get me wrong, I love the area. I just don't love that people seem to think it's tame and safe. It isn't. Still, the fact that it's not safe is at least half the fun. Come summer, try walking up Goodman's Creek from the Lerderderg entrance. It's a fascinating walk, but not signposted and is physically challenging. The creek runs through a deep gully with lots of pools, gold mine tunnels (there's still gold to be found there) and magical plants and wildlife. Zillions of eastern grey kangas and black wallabies. More echidnas than you can shake a stick at. Excellent redfin fishing. Hard to find and no phone coverage but worth it. Ends roughly at the Bacchus Marsh Gisborne road at Bullengarook. Margaret's Corner and the O'Brien crossing are good halfway starting points.
Another place nearby that's not well known is the Antimony range on the eastern side of the road roughly opposite Bullengarook on the northern side of the reservoir. Most southerly outpost of the Mallee scrub and relatively untouched. When the reservoir is low, you can see and explore the old buildings of the previous Coimadai township that was drowned when the reservoir was built. Completely different from the Wombat State forest just over the road even though it's less than a kilometre away. When the black wattle blooms is quite quite magical. Rare orchids too.