Ushuaia exists, in large part, because Argentina wanted somewhere to put people it could not keep anywhere else. The first prisoners arrived in 1884, and the settlement grew around the penal colony the way a town grows around a factory. The logic was the same one Britain used for Australia: an island so far from everything that escape was meaningless, surrounded by freezing seas, walled in by distance. In 1902, inmates began building a proper prison complex of brick and timber. To move the rock, the sand, and above all the lumber that the work demanded, they laid a railway, first on simple wooden rails, with oxen dragging the wagons through the cold.

By 1909 the governor reported that the wooden line could not keep up, and the railway was rebuilt with Decauville track at a narrow 600-millimeter gauge, worked by steam locomotives. The upgraded line opened in 1910, connecting the prison camp with the forestry camp and running along the shore in front of the growing town. Day after day, prison crews rode the line out to the forests beyond the town, felled and loaded the beech, and rode back. The wood heated the cells and cooked the meals; the timber and stone raised the very buildings that held them. Surviving photographs show convicts in heavy coats crowded onto open flatcars, and others bent over a locomotive's machinery in 1931, repairing the engine that carried them. It was punishing labor in punishing weather, and it shaped the town that Ushuaia became.

The penal colony closed in 1947, and a naval base took its place three years later. Without prisoners to work it or wood to haul, the railway fell quiet. Then the earth intervened: the 1949 Tierra del Fuego earthquake tore up much of the line, and for decades the rails lay abandoned, swallowed by the peat bogs and the lenga forest. The train of the prisoners seemed gone for good, a grim chapter the growing tourist town had little reason to revive.

In 1994, a seven-kilometer stretch was rebuilt and reborn, this time for visitors, running into Tierra del Fuego National Park. The line now operates as the Ferrocarril Austral Fueguino, and steam locomotives, among them the Argentine-built Ing. L. D. Porta and a pair of articulated Garratts, haul carriages through native lenga and ñire beech forest, along the Pipo River valley, past peat bogs and the bleached stumps of trees the convicts cut more than a century ago. The route is genuinely beautiful, and genuinely the southernmost working railway on Earth. The pleasure of the ride is real. So is the history beneath it. The forest that the prisoners stripped for fuel has begun, slowly, to grow back, and the train that once carried captives now carries witnesses to where it ran.