Itapuã guards a promontory of hills, beaches, dunes, lagoons, and marshes in the municipality of Viamão, just 57 kilometers from the state capital. The park preserves one of the last remnants of the environment that once covered the entire Porto Alegre metropolitan region, a pocket of the pampas biome held between two enormous expanses of water. Frequent fog drifts across the point, softening the line between land and lake. The first European settlers arrived in 1733 and tried to farm; the land passed through many hands, at one point home to sixty families from the Azores, but it never proved fertile - and that stubborn poverty may be part of why so much of the original landscape survived. At the very tip, where Guaíba's waters slide into the Laguna dos Patos, the Itapuã Lighthouse has stood for more than a century and a half, a small white sentinel watching over the meeting of the two.

For much of the twentieth century, Itapuã was almost lost to the very governments meant to protect it. Land was expropriated in the 1950s, 70s, and 90s with grand plans attached - one decree in 1973 envisioned an "Itapuã Tourist Complex" of resorts and handicraft centers. Instead the state let quarries chew into the rock, allowed illegal summer homes to spread, and tolerated uncontrolled crowds. Scientists and environmentalists protested. In 1985 a coalition of civil society groups formed to fight for the place, the quarries and illegal houses were shut down, and researchers finally moved in to study what remained. The park was formally created in 1991, and authorities then closed it for more than a decade to let the wounded ecosystems heal. It reopened in April 2002.

What that recovery protected is a genuine refuge. The brown howler monkey lives in these forests, locally threatened with extinction, its deep calls carrying across the hills at dawn. Neotropical otters slip through the waterways, and the elusive margay, a small spotted cat, hunts in the canopy. The skies bring travelers from far away: the buff-breasted sandpiper, a long-distance migrant, and the tropical kingbird among them. Around 5,500 hectares of hills and shoreline give all of this room to exist, expanded over time to take in the dark waters of Lagoa Negra and, in 1993, the Pombas, Junco, and Ponta Escura islands. The scale is why the park caps visitors at 350 people per day. On busy Sundays, many who arrive are turned away at the gate. Itapuã's wildness is real precisely because access to it is rationed.

History clings to the rocks as stubbornly as the howlers cling to the trees. Inside the park, a small museum displays weapons and boat parts left by combatants of the Ragamuffin War, the long Farroupilha rebellion that convulsed Rio Grande do Sul from 1835 to 1845. Relics from that conflict still lie at Morro da Fortaleza - Fortress Hill - and on Junco Island, alongside the old Ferraria dos Farrapos. Visitors who come to swim at the park's beaches, walk its ecological trails, or simply watch the fog roll off the lagoon are sharing ground with a near-vanished ecosystem and a nineteenth-century war at once. Itapuã holds both, on the same rocky point, where the two waters meet.