Possibly my favourite and (I feel) most underrated is the Canberra Centenary Trail. This is a 145Km walking/cycling loop of the city of Canberra, that takes-in the city-centre and much of its surrounding bushland. You can walk the trail in a week or ride it in 3 days.
Unfortunately there's no links to Google Maps overlays for it... So I made one.
It has both the walking and cycling routes as separate layers and should be easily sharable.