I like this place to cool off during hot summer days. Have a short walk upriver and let yourself float down by the green and fresh water, sourcing from Lake of Zurich. If you have the guts, throw yourself down the crossing bridge.
For Didierea Trolli, Cyphostemma bainessii and other astonishing creatures from the family of the succulents, take a stroll through the six glasshouses, situated a bit outside the city center along the lakefront.
The Hardbrücke is a long, brutal concrete bridge that runs through a former industrial area. I like the view down to the rail tracks and the many construction sites. And, within spitting distance, you can find a few good places to spend a nice evening, such as Helsinki (for concerts), Rosso (for pizza), and Les Halles (for beer and tapas).