Hann Park is one of Dakar's few large green spaces, with public gardens dating back to the early 20th century and an arboretum planted later. It is not pristine wilderness, but the shade, paths, and birdlife are a welcome change from the traffic and dust of the peninsula.
The zoo is modest and will not satisfy everyone, but families may still find it useful. Treat Hann primarily as a city park and botanical escape, not as a reason to cross Dakar on its own.