Accessible to the city center is the wildlife haven of Costanera Sur Ecological Reserve. (©Arpad Benedek/iStock)
A stretch of marshland reclaimed from the river, with four lakes, willows and shrubs are home to over 150 bird species and iguanas, which have been spotted over the past few years. There are various different entrances. Check for moonlight tours once a month; excellent bird info on the website. Tue-Sun 8am-6pm (in summer 8am-7pm). Admission free.