The Costanera Sur is an area on the east side of Puerto Madero. In 1918 it was inaugurated as a seafront and over the following decades restaurants, bars and dramatic statues brought a level of decadence to the previously run down location. It was one of the favourite spots for residents of Buenos Aires to come to, for the fresh air and to bathe in the river. During the 60s this decadence turned to decay and establishments started to close and signs appeared warning people not to swim in the increasingly contaminated water.
During the 70s and 80s, in a period when the military government was expanding the urban road system by building monstrous highways leading into the city, a large amount of rubble was left to be disposed of. It was decided that it would be dumped in the river, in a land reclamation project which reached from the north of the city all the way down to the port of La Boca. Originally there were grand plans to use this new land to construct an administrative centre for the city, as well as developing the city further eastwards. These plans were soon abandoned, although debris continued to be dumped until 1984.
The water which had been largely drained from within the rubble embankments formed ponds and grasslands. Seeds, which were present in the silt from the river or deposited by the wind and animals, started to grow into a variety of plant communities. This provided food and refuge for animals to settle down, which led to an ever-increasing biological diversity.
Attracting naturalists, joggers, students and bird-watchers, the area began to regain popularity, while environmental organisations were calling for the government to protect the land. In 1986 the Buenos Aires government unanimously voted to do so, leading to what is now the Ecological Reserve, visited by more than one million people every year. Located in a prime location, the area is envied by property developers who continue to build towering skyscrapers alongside
The area is well maintained by a group of workers, who provide protection against invasive species of plants and animals. Open during the day to city visitors, the reserve provides a haven of tranquillity which many take advantage of. The wide dusty paths are continuously strolled along, while bike riders also like to cycle in an area free of cars, buses and motorbikes. The paths lead down to an area on the edge of the river with picnic tables and trees for protection from the sun, although the wind comes charging in from the river and helps to create the impression of a genuine seaside location.
The reserve is open every day except Monday, from 8am to 6pm. Guided tours are offered at 10.30am and 3.30pm on Saturdays and Sundays, providing a deeper experience of the nature and wildlife. Every full moon the reserve conducts a night trail as well, although this is hugely popular and a space must be reserved a few days in advance. Bird-watchers convene on a monthly basis, details of which are given in the office at the main entrance to the reserva. There are also regular volunteer days, when the general public are asked to come along and help in various tasks, such as planting new species of vegetation.
There are two entrances to the reserve, both located on the Costanera Sur. One is found by following Avenida Cordoba to its eastern end, while the main entrance is reached by following Avenida Belgrano to its eastern end.