On April 22, 1779, the Spanish explorer Francisco de Viedma y Narváez planted a fort on the southern bank of the river and named the settlement Nuestra Señora del Carmen. It was the first European foothold in all of Patagonia. The original fort washed out within months, so a second went up on the higher northern bank, and for a century the two banks grew as a single town. That northern settlement earned its own page in history in 1827, when an improvised force of gauchos, freed Africans, and corsairs threw back an invading Brazilian fleet and captured seven of its flags, a victory the townsfolk still celebrate every March. Then, in 1878, the new Patagonian territorial government split the twin towns. The northern half kept the old name, Carmen de Patagones; the southern half took the explorer's surname. Across the brown water, the two still face each other like old siblings who divided the family house but never moved away.

Twice this modest town stood at the edge of enormous consequence. After the Conquest of the Desert opened Patagonia to settlement, Viedma became capital of the whole vast territory, then of Río Negro Province alone. Far stranger was 1986, when President Raúl Alfonsín proposed moving Argentina's federal capital here from Buenos Aires, a bold gesture meant to pull the nation's gravity southward toward the empty land. Congress passed the relocation law in 1987. Then the economy collapsed, Alfonsín left office, and his successor Carlos Menem quietly shelved the whole idea. The ministries never came. Viedma went back to being itself, the capital of a province rather than a nation.

The pleasures here are deliberately small. A footpath traces the Río Negro shoreline, where the water runs wide and slow between flat banks, and where bathing is possible from November through March in waters warmed by the Patagonian summer. A cheap little ferry shuttles across to Carmen de Patagones, though in low tides with high winds the operator simply cancels and posts the suspension online. Between Plaza Alsina, where the cathedral stands, and Plaza San Martín to the north, the old buildings cluster within an easy walk. The streets are wide and flat, the traffic occasional, and the whole compact center invites the slow pace of a town in no hurry to impress anyone.

Viedma's real gift is what lies beyond it. Thirty kilometers southeast, where the Río Negro empties into the Atlantic, the beaches begin, a string of little-known shores that few outsiders ever reach. Balneario El Cóndor opens the sequence with a vast sandy beach and a cliff colony of parrots so large it is famous among ornithologists worldwide. Farther south, La Lobería shelters a sea-lion colony on a rocky, picturesque shore. The coast unspools westward through Bahía Creek's blue-water bay all the way to San Antonio Oeste and the caves of Las Grutas. From this unhurried capital, the wild edge of Patagonia is only a local bus ride away.