The Costanera Sur Ecological Reserve in Buenos Aires is a massive green space right in the heart of the city, located behind Puerto Madero.
Originally reclaimed from the river, this urban oasis is now a haven for over 300 bird species and 500 types of native plants. In other words, perk up bird watchers. This is your spot! You can book tours with bird watching guides to see over 300 species right in the middle of the city.
If you rent a bike, this is a great spot for a ride or without a bike, for a relaxing walk to get out of the city center.