One of the World's Bike Paradise is Carretera Austral that runs more than 1350 kms linking Villa O'Higgins to Puerto Montt, in the Chilean Patagonia. Actually (January 2005) there are about 1000 kms of gravelled road (locally called ripio) and a little bit less than 300 kms of asphalted road, the rest is done by ferries. Along the whole  path it is possible to find an incredible variety of mountains, lakes, glaciers and woods that make this land one of the World's wonders.   
Many corners of this green paradise are almost unknown and the Wilderness is the absolute queen. The bike permits to explore the region in a great way. If You are in good shape and with an equipment well fitted for the hard "ripio", try to cycle the Carretera on your owns alone or with some friends, try to pitch your tent along a wild river or in a wood..try to sleep inside listening to the wind blowing and the rain falling outside..try to cycle for miles and miles meeting anybody, discovering a wonder in every  corner...But try to go there as soon as possible: the Carretera  (and maybe whole Chilean Patagonia) is changing quickly and  it is possible that in a few years more and more roads will be pavemented.......