Santa Teresa breaks the usual rules. Unlike Uruguay's other national parks, it is not run by the country's protected-areas service but by the Park Service of the Army of Uruguay, a legacy of the colonial fortress at its heart. The military stewardship gives the place a distinctive order: tidy plantations of pine and eucalyptus alongside native species, well-kept roads, and a scale of organized recreation that few wild parks attempt. The forest itself is the headline achievement, a planted woodland engineered to stabilize the shifting coastal dunes that once menaced the fort. Walking its shaded avenues, it is easy to forget that this entire canopy is an act of human intention, raised tree by tree across the twentieth century to defend a wall of stone.

The coast is the other half of the park's character. Beaches run for more than 12 kilometers, sweeping from Punta del Diablo in the south to Cerro Verde in the north, wide bands of sand broken here and there by rocky stretches. Each beach has its own personality: Playa Grande, Playa del Barco, Playa Achiras, and Playa la Moza, the last considered to hold the best surfing waves in all of Uruguay. The dunes that Arredondo fought to control still rise behind the sand, and the open South Atlantic rolls in unbroken. Between the planted forest and the working surf, the park offers a rare combination, a managed woodland and a wild ocean edge sharing a single boundary, each shaping the experience of the other.

For a park born of military reforestation, Santa Teresa has a playful streak. The Invernaculo is a botanical garden and greenhouse holding more than 300 plant species, including some found nowhere else in Uruguay and many imported from tropical forests on other continents. El Chorro is a freshwater pond stocked with fish, including large pools of koi, set beside desert plantings of cacti and backed by a restaurant. The aviary houses parrots, toucans, forest songbirds, and other native species, along with small mammals and reptiles, the latter kept, as the park dryly notes, well apart from any creature that might fancy a poultry dinner. These curated attractions make the park feel less like wilderness and more like a vast, century-old garden tended by an army.

Few parks anywhere are built to host crowds on this scale. The campground holds 1,600 sites and can accommodate up to 10,000 overnight guests, from rustic tent pitches under towering shade trees to improved sites with electricity and water, plus cabins, some perched near the beach with sweeping ocean views, and a hostel with dorms and private rooms. Admission to the park itself is free, with fees only for staying the night, and overnight guests get round-the-clock access while day visitors keep to daytime hours, Tuesday through Sunday. It is a democratic kind of grandeur, a forest and coastline that Uruguay deliberately built to be shared, where the same trees that once saved a fort now shelter thousands of tents each summer.