The historic grounds of the garden were later extended outside the city wall. These areas are connected by three historic tunnels that intersect the Wall. Within the wall are several publicly accessible greenhouses (historic fern house, orangery, cold house, rainforest house, cycad house, Araceae house, succulent house, cactus house) and institute building. Outside the Wall there is a system of the latest phylogenetic findings as well as an alpinum with different habitats, a historical garden and an arboretum.
The garden has about 100,000 visitors a year.