Wild Buenos Aires: the Costanera Sur Wetlands and the Delta

The wild side of Buenos Aires, from the lagoons, marshes and woods of the Reserva Ecológica Costanera Sur, a Ramsar wetland beside Puerto Madero, to the islands and rivers of the Paraná Delta and the parks of Palermo, with a directory of the places in our guide. Facts from the City of Buenos Aires and the Ramsar Convention.

Buenos Aires is a city of avenues and cafés, but it stands on one of the great rivers of the world, and the wild is closer than it looks. Between Puerto Madero and the Río de la Plata, lagoons and reed beds hold hundreds of species of birds; north of the city, the Paraná Delta begins at Tigre, a maze of islands and rivers you explore by launch.

This is a short, honest guide: the city’s nature is about birds, water and green space rather than big animals. Come early, bring binoculars, and enjoy the quiet.

The largest green space in Buenos Aires is a wetland of international importance, a short walk from the towers of Puerto Madero.

The Reserva Ecológica Costanera Sur

The Reserva Ecológica Costanera Sur stretches between Puerto Madero and the Río de la Plata. At 350 hectares it is the largest green space in the city, a mosaic of woods, grassland, lagoons and marshes where the native plants and animals of the river shore live within sight of the towers. Birdwatchers come at dawn; since 2023, new interpretive boardwalks run over the old footpaths, so that older visitors, people with disabilities and children can enjoy it too. The reserve is run by the city: take water and a hat.

The delta and the parks

North of the city, Tigre stands where the Paraná Delta begins: a maze of islands and rivers where houses stand on stilts and the shopping, school runs and post all go by boat. Launches leave Tigre’s river station for the islands, some as tours and some as local river buses; the Mitre line runs from Retiro to Tigre.

In the city, the Bosques de Palermo spread across the north with lakes, woods and lawns around the Rosedal; nearby, the Jardín Botánico Carlos Thays gathers plants from across Argentina under old trees and an iron-and-glass greenhouse, and the Japanese Garden has a lake and bridges in the Parque Tres de Febrero.

Feature: a wetland of world importance

In 2005 the Reserva Ecológica Costanera Sur was declared a Ramsar site, a wetland of international importance, and BirdLife International lists it as an Important Bird Area. It is also part of the Ecoruta del Río de la Plata, a circuit of more than 100 kilometres linking the green spaces and protected areas of greater Buenos Aires.

Did you know? With 350 hectares of woods, grassland and lagoons, the Costanera Sur reserve is, in the city’s own words, the largest green space in Buenos Aires.

Our advice

Our advice: go to the Costanera Sur at dawn, when the birds are busiest and the paths are quiet, with binoculars, water and a hat. Take the Mitre line to Tigre for a launch into the delta, and give the Bosques de Palermo a slow afternoon. Never feed the birds or other animals.