"Just adjacent to the newest and most expensive neighborhood in Buenos Aires is an 865-acre ecological park. The Costanera Sur reserve is one of the few spots in the city that really embraces the beauty of Río de la Plata, the massive river that hugs Buenos Aires’ coastline. It’s also one of the last remaining green spaces rich with the area’s native flora and fauna, and the single best option for bird watching inside city limits.The reserve has several trails and cycling paths that offer panoramic views of the city landscape, with skyscrapers in the background and native plants in the forefront. It’s also a good spot for a quiet picnic, and an escape from the noise of the city. The ecological park is open every day except Mondays, with free entrance and tours you can book in advance (call ahead to schedule a tour in English). We recommend taking a tour at night on the Friday closest to a full moon." - MATADOR_NETWORK