The Botanical Garden covers about 10 hectares in the Bernsdorf district, north of the centre, and has been open since 1945. It's a working scientific collection as well as a public park, with around 10,000 plant species from across the world. The greenhouses hold tropical and succulent collections; the outdoor beds are organized by geography and by plant family.
It's an unhurried place, well maintained and rarely crowded outside summer weekends. Entry is free. The garden is a reasonable destination in its own right on a fine day, or can be combined with a visit to the Küchwald park nearby, which is where the Parkeisenbahn narrow-gauge railway runs.