Cincinnati, United States of America
The Mount Airy Forest, in Cincinnati, Ohio, was established in 1911. It was one of the earliest, if not the first, urban reforestation project in the United States. With nearly 1,500 acres (6.1 km2), it's the largest park in Cincinnati's park system.
Listen to the audio guide for Mount Airy Forest Free on WIP — starts by itself when you arrive, even with the screen off