Grampians National Park.
It comprises 1,672 square kilometers of sandstone mountains, forest, rivers and good hiking trails and, being this close to Melbourne, is a popular holiday destination.
Having said that I had no trouble getting accommodation which might be because its winter down here, and the arrival at Halls Gap wasn't promising, with thunderous rain drumming on the car roof.
However it sort of worked out, with just the odd shower while I was walking, and anyhow its just water, and meant there was no worries about forest fires that have blighted the region in the past.
So I hiked the Wonderland trail via the Grand Canyon (more petite than grand to be honest) to the Pinnacle lookout (above) and also down the many steps to the base of the MacKenzie Falls (below):