In Chile.
Mike Howarth:
… a grand feat of engineering linking the remote and isolated communities of Puerto Montt in the north with Villa O’Higgins in the south. Perhaps a curiouser byproduct is that of the adoption of this rough isolated road spanning 1200 kms by cyclists. Voted one of the top ten cycling destinations in the world, each year more and more come to make their pilgrimage to the holy grail of adventurous cycling. …
see Mike’s photo journal – Carretera Austral: A Ripio Oddeseey
There’s GREAT access to remote hiking from that roadway, by the way.
besthike.com 
The hiking in this area would be amazing with magnificent hiking in many of the national parks that scatter the road.
I’m sure you could while away a good few months in the parks with out even touching the better known parks like El Chalten.