Evolving from the Baroque style Pharmaceutical Garden founded by Empress Maria Theresia of Austria in 1754, this botanical garden cultivates over 9000 types of plant and tree which include numerous endangered specimens. Plants are grouped together according to their geographical pedigree and include succulents, alpine floras and vegetation of Austria, as well as cacti, orchids and tropical plants. The Alpinium is well worth a look with its varieties covering the mountainous regions of Austria and beyond. The now restored greenhouses, built between 1890 and 1893, are used mainly for research purposes although one holds a rainforest exhibition for visitors.