The Cabo Froward Trail starts at the end of Highway 9 south of Punta Arenas, and follows the coast to Cabo Froward, the southernmost point on the continent of South America (further south are only islands). Return the same way, for about 79km round trip.

There is a minimally supported race on this trail each year:  https://rodrigo3947.wixsite.com/cabofroward

Another feature for Oregon Rails-to-Trails, submitted by Jason Hardrath:

Row River Trail