Staklenik, Zagreb Botanical Garden

The Botanical Garden of the Faculty of Science in Zagreb was founded in 1889 by Professor Antun Heinz, who had spent a year studying European botanical gardens. Work began in 1890 with head gardener Durchánek, and the first planting took place in 1892. The exhibition greenhouses were built in 1891 to Heinz's specifications by the contractors Šafranek & Wiesner, after the city approved the plans on 3 April 1891; some sources date the building to 1892. According to a recent study, the ironwork came from the same manufacturer as Vienna's Palmenhaus.

In 1911 a marine aquarium was installed in the greenhouse, whose southern entrance was removed for the purpose, and for some years it was one of the city's attractions. In 1955 the central lantern pavilion and the aquarium were demolished and replaced by a plainer, taller palm house, partly because of maintenance costs. After a century of coal heating, the greenhouses received a central gas boiler plant in 1989. The garden has been protected as a monument of landscape architecture since 1971.

A full restoration was prepared from 2012; work began in 2016-2017 and the northern brick entrance building was renovated around 2018. The project then stalled for lack of funding, and the 2020 Zagreb earthquake damaged the load-bearing structure. At the end of 2023 the historic greenhouse was still fenced off and closed to visitors, awaiting EU funds, with costs estimated at 2.5 to over 3 million euros.

The complex measures 24.05 by 21 metres externally and comprises five compartments with separate heating regimes. The taller central pavilion was crowned by a glazed lantern and flanked by two side wings, one heated and one cold. The structure is of iron and glass, with triangular trusses whose lower chords are curved, glazed with green glass tinted by copper oxide. The metal was painted the pale green then fashionable in Vienna.

To the north, foundation walls of exposed brick and a brick entrance building close the ensemble; inside, the north wall, rusticated with fragments of stone and brick, supported climbing plants. Walkways running above the ridge allowed staff to work the shading blinds and observe the plants. A basement housed the coal boiler and the pipe network. The restoration project provides for six automated climate zones and the reinstatement of the central lantern pavilion.

Designed to display exotic plants in different thermal settings, the greenhouse has notably been used to overwinter palms in its tall central volume. The garden's glasshouse plants are now spread across newer structures built in 1985, 1995 (a domed greenhouse west of the parterre) and 1996. The garden, covering 4 to 5 hectares, holds several thousand taxa and a significant collection of Croatian flora. Once restored, the historic greenhouse is to become a visitor centre housing the country's first seed bank for native flora.

The garden also preserves its geometric western parterre with the fountain basins of 1891, restored in 2004-2006. While the historic greenhouses remain closed they can only be seen from outside. The garden itself opens from late winter or spring until autumn and closes during the cold season. Set on Marulić Square, it forms part of Lenuci's Horseshoe, the chain of squares and parks in central Zagreb, and combines easily with a walk to the main railway station and King Tomislav Square.