Once past the Beagle Channel, there's not much left between the ship and Antarctica. Puerto Williams clings to the north shore of Navarino Island, facing the mountains of Argentine Tierra del Fuego, and claims the title of the southernmost town on the planet. A few thousand residents, sheet-metal roofs huddled against the wind, a naval base, a grid of short streets: the place can be understood in a morning, yet it leaves a lasting impression. Expedition ships bound for Cape Horn or the Antarctic Peninsula stop here for formalities, and above all to give their passengers one last contact with the inhabited world.

A village at the edge of the map

Ashore, everything can be explored on foot. The central square, the murals devoted to the region's peoples, the small church and the supply stores make up an unadorned setting, where residents readily greet the few passengers passing through. Horses sometimes graze freely between the fences, dogs casually escort walkers, and the smoke from wood stoves scents the streets as soon as the temperature drops, which is to say often. On the high ground of the village, the bow of the Yelcho, the tugboat that rescued Shackleton's crew in 1916, is a reminder that the history of the southern seas often played out in these waters.

The memory of the Yaghan people

The Martín Gusinde Museum, named after the missionary and ethnologist who documented the Fuegian peoples, occupies a few well-kept rooms in the heart of the village. Here you follow the trail of the Yaghan, seafarers who travelled the channels in bark canoes, with a fire kept burning on board, long before European sailing ships arrived. A short walk away, the hamlet of Ukika is home to families descended from this people. A visit to the museum sheds light on the rest of the port call: afterward, every island in the Beagle seems to bear a name older than those on the maps.

Forests no taller than your hand

At the edge of the village, Omora Ethnobotanical Park protects a realm best viewed through a magnifying glass. Here, mosses, lichens and liverworts form miniature forests of astonishing diversity, which short trails allow you to observe with a guide. Bending down toward these tiny gardens while the wind shakes the lenga trees overhead charmingly reverses the scale of southern landscapes. The researchers who work here speak of "tourism with a hand lens," and the phrase describes the experience exactly.

Hiking up Cerro Bandera

The more energetic tackle the Cerro Bandera trail, which climbs steeply through the forest before emerging onto the summit tundra. Up top, a Chilean flag snaps relentlessly above the Beagle Channel, with the Dientes de Navarino behind you, a crown of jagged peaks that draws long-distance hikers. Allow half a day round trip, good shoes and a serious windbreaker; the reward is measured in kilometres of channels unfolding before your eyes.

The gateway to Cape Horn

Many passengers set off from here toward the south, where the Americas crumble into wave-battered islets. Puerto Williams serves as the gateway to these latitudes: you mail one last postcard, watch for petrels from the pier and take stock of your luck at going farther. Local excursions on the channel round out the port call for those who stay, among seabird colonies and roadless shores.

What stays with you offshore

When the ship heads back into the channel, the village quickly disappears behind a curtain of drizzle or a break of sunshine, depending on the mood of the day. What remains are the dwarf forests, the museum's bark canoes and that lone flag atop its hill. Few port calls this brief take up so much space in the memory of a southern voyage.