Sydney's Grand Canyon looks like a benign Jurassic Park with beautiful creeks, waterfalls, caves, lizards, and ferns. Situated just past Blackheath in the Blue Mountains, it's a perfect day away from the congestion of city life. With air so fresh you'll be left wondering what you were breathing back in Sydney, and silence but for your own heavy breathing (the winding stone steps get steep), it's the stress-relieving, endorphin-releasing walk you need between busy work weeks.
The Grand Canyon Track is partially closed at the moment, but the section that's open is worth the hike. Just grab a friend, some snacks to keep you energised, and be on your way. Start at Evans Lookout and follow the signs. When you're done, I promise you'll be in a better mood than when you arrived.
Practicalities: 2-2.5 hours from Sydney, your trusty GPS will guide the way if you put in 'Evans Lookout'. Give yourself 1-2 hours for the section of the walk that is still open, and don't forget sunscreen and water!