Steklenjak (exhibition glasshouses), Volčji Potok Arboretum

The park at Volčji Potok owes its shape to the Souvan family. In 1882 Ferdinand Souvan, a Ljubljana wholesale merchant, bought the estate from the widow of Ferdinand Gozani; in 1885 he rebuilt the manor and laid out a walled park in front of it. His son Leon later pulled down the wall, enlarged the park over half a century, planted native and exotic trees and dug ponds. Partisans burned the manor on 13 April 1944 (15 April according to the English Wikipedia). After Leon Souvan's death in 1949 the estate was nationalised, protected by a decree of 1950 and placed, at the beginning of 1952, under the Faculty of Agronomy and Forestry of the University of Ljubljana, which turned it into an arboretum opened to the public that same year.

Greenhouses enter the story under the direction of Igor Oraš (1957-1961): the park reached 80 hectares, the lake in Jelova draga was dug and the nursery was modernised, greenhouses and cold frames included. When the link with the university broke in 1965, the institution had to live from production and services; its flower shows, dominated by tulips, carried it through the lean years. The arboretum was declared a cultural monument of national importance in 1999 and later became a state public institute (in 2003 according to the English Wikipedia).

Dušan Hrovatin's cactus collection has been shown there since at least 2012, at that time from March until late autumn, before becoming a year-round exhibition in 2026; live tropical butterflies were already flying under the glass in the summer of 2022. In February 2026 the orchid house was partly refitted with new arched frames. With 390,420 visitors in 2025, 11.6 per cent more than the year before, the park is Slovenia's most visited heritage site after the castles of Ljubljana and Predjama.

The arboretum's website names the venue with a single word, 'Steklenjak', the glasshouse, yet elsewhere speaks of the 'glasshouses by the pristava', the farm building of the old estate, and the kraji.eu portal places them behind the former administration building. Photographs uploaded to Wikimedia Commons in July 2022 show the inside of the cactus house: a gable-roofed glasshouse with a light metal frame and clear glazing, a central aisle running between raised stone-walled beds in which the plants grow in the ground or in labelled pots. The neighbouring house, devoted to orchids, bromeliads and houseplants, is kept in a tropical climate that, as the site points out, only a glasshouse can provide; in February 2026 the space was partly rearranged, with new arch-shaped frames giving rhythm to the display and a photo corner. The tropical butterflies fly within the same complex, among nectar plants grown in planting boxes.

In OpenStreetMap, the parcels of the Slovenian land-use register classed as greenhouses lie immediately south of the administration building, in the western part of the park, between the orchard and the nursery.

The cactus house brings together more than a thousand plants from Dušan Hrovatin's collection (shown in 2012 under the name Hrovatin Exotica), remarkable for their variety and their age: the oldest specimen in the house is fifty years old. Around the cacti stand succulents, bulbs, euphorbias, tillandsias, crested forms and 'living stones' from the arid regions of Africa, whose two fleshy leaves mimic the colour of the gravel and which flower only once a year, around September. The second house combines tropical orchids, Vanda among them, bromeliads (the site devotes articles to guzmanias, vrieseas, aechmeas, tillandsias and the dwarf pineapple) and a selection of foliage houseplants, renewed in three cycles a year and accompanied by care instructions. In season, live tropical butterflies, which feed on citrus, fly among the flowers; in 2022 the arboretum named the morpho Morpho peleides, Danaus chrysippus, Heliconius melpomene and the owl butterfly Caligo memnon, recognisable by the large eyespots on its wings.

The glasshouses stand by the pristava in the old part of the park, not far from the administration building and the Janez Boljka gallery, where a multimedia display tells the story of the Souvans and their park. Their visit fits into a day given over to the arboretum's roughly 85 hectares: tulips in April, the best-attended show, rhododendrons in May, the rose gardens in June, dahlias in late summer, pumpkins in autumn and an evening walk among the lights from late November to January. The lookout tower opened in 2023 overlooks the Kamnik Alps and, in the distance, Ljubljana Castle; children have a large playground, thirteen life-size dinosaurs and a road train. Buses run from Ljubljana and Kamnik (Volčji Potok Šraj stop, 300 m from the entrance), and a cycle path follows the Kamniška Bistrica; the nearby town of Kamnik rounds off the outing.