Cactus Exhibition Greenhouse, University Botanical Garden Balchik

The garden occupies the grounds of Queen Marie of Romania's former summer palace at Balchik, an architectural and landscape ensemble laid out in terraces linked by steep stairways. In 1955 the land was handed to Sofia University 'St Kliment Ohridski' to create a botanical garden under academician Daki Yordanov; the site is now a cultural monument and a protected area.

The cactus and succulent collection arrived in the mid-1960s, moved from the Sofia botanical garden. For decades its large specimens spent the warm months outdoors and had to be relocated every year for the winter. In September 2008 the news site News.bg reported plans for a new 800 m² tropical greenhouse on four levels in the garden's service yard, intended both as an exhibition and a production space for tropical and subtropical plants, orchids and cacti, and meant to end those seasonal moves.

In 2012 a permanent exhibition of cacti and succulents opened in a purpose-built greenhouse, open all year. The sources consulted do not state explicitly whether this is the building announced in 2008.

The available sources describe the greenhouse mainly through its use. The project announced in 2008 called for an 800 m² glass building on four levels, each kept at a different temperature and humidity, in the garden's service yard. Such a stepped arrangement suits the estate, which is built in terraces on the slope running down to the Black Sea.

According to a 2020 description, the exhibition opened in 2012 stages the transition from desert to Mediterranean vegetation. The glasshouse also serves as a winter shelter: in 2018 the garden's director explained that under its glass roof the heat-loving plants spent the cold season at 15 °C and could even flower there, while a 2020 article gives a minimum of 12 °C. Neither the architect nor the builder is named.

The cactus and succulent holdings are reputed to be the second-largest in Europe after Monaco's; published figures vary from article to article, from about 600 species to nearly 3,000 varieties. Some specimens are more than sixty years old. Most of the giants belong to the genus Opuntia, the agave family (Agavaceae) and the spurge family (Euphorbiaceae), and there are aloes too, among them Aloe pruinosa, endemic to KwaZulu-Natal. In 2008 an Agave angustifolia about fifty years old was about to flower for the first time.

Each autumn around 700 large plants, some weighing 650 to 700 kg, are carried in by hand from the 'Divine Garden', a 680 m² open-air display. The garden's glasshouses also produce exotic fruit such as bananas and papayas, and lemons the size of a handball.

The greenhouse stands in the University Botanical Garden, at the heart of Queen Marie's palace complex on the Balchik seafront. The 194-decare garden is explored on terraces; allow half a day to combine it with the neighbouring villas and palace. During the cold season the greenhouse holds the whole cactus collection; from late April the largest specimens return to the open-air 'Divine Garden', so the visit is rewarding in any season. The nursery garden, opened in 2005, accessible to visitors with disabilities and labelled in Braille, completes the route.