The University of Wrocław's botanical garden, founded in 1811 and one of the oldest in Poland. Tucked into a quiet block immediately north of the cathedral on Ostrów Tumski, the garden holds over 11,000 plant species across seven hectares — alpine rockeries, tropical glasshouses, a large arboretum, and a separate dendrological garden across the river.
A small admission fee, open March through November. Combine with a visit to the cathedral on a long afternoon.