🇦🇷 Argentina · Buenos Aires
In the middle of the pampas plain, right where you would least expect it, the southwest of Buenos Aires province hides a chain of very old hills: the Ventania range, better known as the Sierras de la Ventana. These are not the Andes —the highest point, Cerro Tres Picos, is around 1239 metres— but in the middle of the flat pampa these mountains of grey rock and golden slopes are an apparition. The plan here is to walk, to climb, to head into gorges with waterfalls and to be surprised by the 'ventana': a natural gap or hole punched through the rock of Cerro Ventana, which gives the whole comarca its name and stands out against the sky.
The comarca is really a jigsaw of villages: Sierra de la Ventana proper, on the Sauce Grande river, with its mountain-village air and its suspension bridge; Villa Ventana, smaller, wooded and quiet; and nearby Tornquist, the district seat. Its natural heart is Ernesto Tornquist Provincial Park, a protected area of hill grassland, native wildlife and trails for every level, from one-hour family walks to full-day crossings.
Sierra de la Ventana is the Buenos Aires province destination par excellence for trekking, adventure travel and time in nature: summit climbs, horseback riding, mountain biking, rappelling, paragliding, river swimming spots and campsites among the hills. But it also holds layers of history: the Indigenous peoples who revered these hills, the 19th-century frontier forts, the legacy of the magnate Ernesto Tornquist and the ruins of the legendary Club Hotel, a witness to a golden age. Nature, adventure and history a day's travel from Buenos Aires.
Long before today's villages, the Sierras de la Ventana were the territory of Indigenous communities —the Chechehet, or 'hill pampas', related to the Querandí, and later groups tied to the Pampa and Mapuche peoples— who ranged across and revered these hills; the 'ventana' of Cerro Ventana appears in their accounts as the dwelling place of powers or deities. Through the 19th century the region was frontier country: around 1833, as part of Juan Manuel de Rosas's Desert Campaign, way stations and forts were set up on the Sauce Grande river to secure communication with Bahía Blanca, among them the one later called Fortín Pavón. The great transformation came with Ernesto Tornquist, a magnate of German-Swedish descent who in the late 19th century drove the agricultural settlement of southwestern Buenos Aires province and founded the town that bears his name (1883). His family played a key role in the area: in 1937 Martín Tornquist ceded part of his land to the Province to create Ernesto Tornquist Provincial Park and preserve the hill landscape. The village of Sierra de la Ventana grew up around a Ferrocarril Sud railway station in the early 20th century, tied to the building of the luxurious Club Hotel de la Ventana, opened in 1911 near Villa Ventana and considered in its day an emblem of elite tourism; a fire consumed it in 1983 and today its ruins are a historic attraction. The full story is on our history page.
Read the full history ↓The agro-export heart of Argentina: the endless pampa that was the land of the Querandí and the Pampa peoples, the domain of governor Rosas, the engine of cattle and wheat with La Plata as its purpose-built capital, cradle of the gaucho and of the Atlantic Coast where the whole country spends its summer.
Read the history of Buenos Aires Province →No exact prices: a scale from $ (budget) to $$$$$ (luxury), with 2-3 options per category.
Origins, formation and what the sources say.
These hills are far older than the Andes: the Ventania range folded some 280 million years ago, before dinosaurs even appeared, and erosion has been polishing it ever since, leaving the grey rock crests that rise today, unexpectedly, in the middle of the pampas plain of southwestern Buenos Aires province. Long before Europeans arrived, this territory was inhabited and travelled by Indigenous communities. Among them the sources name the Chechehet, or 'hill pampas', groups related to the Querandí, and later populations tied to the Pampa peoples and to the Mapuche-Tehuelche expansion that ranged across the pampa and Patagonia.
For these peoples the hills were not just a geographical feature: they were a landmark, a hunting ground and a meeting place, and also a matter of belief. The 'ventana' of Cerro Ventana —that natural hole in the rock— appears in stories and legends as a place charged with meaning, associated with powers or deities. The caves and rock shelters of the area, such as the Cueva del Toro and the Alero Corpus Christi, preserve rock paintings that are direct evidence of that human presence going back millennia.
The water of the hills —streams, springs and the Sauce Grande river— and the abundance of wildlife made Ventania a valuable territory. That deep relationship between the Indigenous peoples and the mountains is the first layer of a history that would later add frontier forts, railways and luxury hotels, but that began thousands of years ago with the people who first saw the window cut into the sky.
For much of the 19th century, southwestern Buenos Aires province was frontier country between the state then taking shape and Indigenous territories. The Sierras de la Ventana, with their water and their natural passes, were a strategic point on that board. In that context way stations, forts and small outposts were set up to watch the roads, secure communications and sustain the advance of occupation across the pampa.
One landmark of that period dates to 1833, as part of the Desert Campaign led by Juan Manuel de Rosas: a watch post was established on the Sauce Grande river —in the area of today's Saldungaray— for a garrison meant to guarantee defence and communication with neighbouring Bahía Blanca. That frontier post would come to be known as Fortín Pavón, a name that stuck around 1863. It was one of several forts and outposts dotted across the region.
Life in these outposts was hard: small isolated garrisons, exposed to the severe hill weather and to the clashes that came with the frontier, in an age of raids and military campaigns. That often dramatic period left its mark on the comarca's place names and historic sites, and it came just before the great transformation that would arrive at the end of the century with the railway and the agricultural settlement driven by figures such as Ernesto Tornquist.
In the late 19th century one figure changed the fate of the region: Ernesto Tornquist, a powerful businessman and financier of German-Swedish descent, one of the great fortunes of Argentina in his day. Tornquist drove the agricultural settlement of southwestern Buenos Aires province and, in 1883, founded the town that bears his name, seat of the district where Sierra de la Ventana lies today. His name has been tied to the comarca ever since.
The arrival of the Ferrocarril Sud railway was decisive. The tracks brought the region closer to Buenos Aires and Bahía Blanca, made it possible to move farm produce and, in time, opened the door to tourism. The village of Sierra de la Ventana itself grew up in the early 20th century around a railway station set down in the middle of the hills, tied to the building of a grand luxury hotel. The place was originally called 'Villa Tívoli Argentino', for its resemblance to the Italian town of Tivoli, and around 1912 took the name Sierra de la Ventana.
The Tornquist family's legacy was environmental too. In 1937 Martín Tornquist ceded part of his hill land to the Province of Buenos Aires to create Ernesto Tornquist Provincial Park, in order to preserve the beauty and the unique ecosystem of the range. That donation gave rise to the protected natural area that is today the heart of tourism in the comarca, with its trails, its native wildlife and the emblematic Cerro Ventana. The old wrought-iron gates that stand at the entrance to the pass belonged, precisely, to a family property.
The most spectacular symbol of that golden age was the Club Hotel de la Ventana, a luxurious complex put up by interests tied to the Ferrocarril Sud railway near Villa Ventana. Designed by the Italian architect Antonio Gherardi and opened on 11 November 1911, it was conceived as an elite resort, with a casino, ballrooms and every comfort of the day, at the height of Argentina's Belle Époque.
The opening was an event: hundreds of distinguished guests attended, among them figures from national politics. The hotel set out to attract the Buenos Aires high society that was already summering elsewhere, offering it hill air, landscape and luxury a few hours away by train. For decades its silhouette among the hills was a byword for glamour and for a kind of tourism designed for the well-off.
The Club Hotel's story had a dramatic ending, however. After various uses through the 20th century —including spells of decline, closures and partial reopenings, as the elite tourism of the early century shifted its destinations and its style— the building was consumed by fire in 1983. Today its imposing stone ruins survive on the outskirts of Villa Ventana, turned into a historic site heavy with nostalgia and local legends about ghosts and the parties of another age, which visitors walk through imagining the lost splendour among the blackened walls and the arches that no longer hold up any roof.
As the Club Hotel declined, Sierra de la Ventana and Villa Ventana were building a more modest but steady tourism, tied to second homes, school camps and families discovering trekking and hill air as an alternative to the beach. That change of scale —from elite luxury to family and adventure travel— is, at bottom, the same transformation much of Argentine tourism went through across the 20th century, and in this comarca it left two visible layers stacked on top of each other: the ruins of a golden age, and the trails, cabins and shelters of the Ventania you visit today. Together with Cerro Ventana, the frontier forts and Tornquist Park, those ruins complete the story of a comarca where age-old nature, the frontier and luxury tourism intertwine a day's travel from Buenos Aires.