The only building at Cabo Polonio wired to the mains is its lighthouse, working since 1881. The cape is a low granite point on the Atlantic coast of Uruguay, held to the land by sand, and no road reaches it. The way in is an open truck across seven kilometres of dune, scrub and shallow water. You stand in the bed and hang on as the chassis pitches, until the last ridge drops away and the lighthouse is there. The old way in is three hours on foot from Valizas, over open dunes. About 130 people live here all year in timber and stone shacks called ranchos, lit by solar panels, small turbines and candles, their water pulled by hand from wells in the sand. With no harbour, the fishermen run their boats straight up the beach and gut the catch there, and the kitchens cook whatever came in that morning; the families running them descend from the sealers.
Offshore lie three low rocks that hold one of only two seal breeding colonies in the country. Two species share them, and they sort themselves out once you look: the fur seal small, dark and pointed in the face; the sea lion twice the size, its bulls with a heavy mane, holding harems through December and January. The rocks under the lighthouse put you as close as anyone gets from land. On a calm night the village hears them, a low unbroken roar under the surf. Inside the tower, 132 narrow steps put the two beaches and the islets below you. Once the last candles go out there is nothing left to compete with the sky: no street lamps, no glow on any horizon. From May to August the core of the Milky Way stands almost overhead at midnight, while the beam wheels silently above the sand. Southern right whales pass a few hundred metres out between July and October, the tall V-shaped blow giving them away first. The same rocks were a killing ground until 1991, when Uruguay finally banned commercial sealing, and the colony has been growing ever since.