Observatoire du Monde des Plantes (University of Liège botanical garden greenhouses, Sart-Tilman)

The Observatoire du Monde des Plantes (OMP) is the University of Liège's botanical garden on the Sart-Tilman campus, about 6.6 km from the historic greenhouses of the city-centre botanical garden, which appear separately in this atlas. The official site says the complex was created between 1992 and 1996; the Wikipedia article on the Espaces botaniques universitaires de Liège gives 1996.

According to a visitor's blog, the place went through a period of neglect before the non-profit Espaces botaniques universitaires de Liège took it over in 2008 to revitalise it; the blog dates the reopening to 18 September 2010, and the official site says only 2010. The association, formed in 2008, brings together four university sites: the OMP, the Sart-Tilman botanical garden and arboretum, the Jardin du Monde and the historic greenhouses of the Liège botanical garden; the whole covers 21 hectares and addresses schoolchildren, students, the public and researchers. The OMP is now part of the university's museum and cultural hub.

In October 2025 RTBF noted that these greenhouses, heated with fuel oil, use a lot of energy and water, and that the team was looking for more sustainable solutions.

The official site speaks of a greenhouse complex of 2,300 m²; a visitor's blog gives 2,000 m² of modern-built greenhouses. OpenStreetMap traces the whole as a single building of slightly over 2,300 m². Photographs on Wikimedia Commons show glass roofs on a metal frame above paths, stone walls and planted beds.

The site has four thematic greenhouses, which recreate three biomes: humid tropical and subtropical forests, Mediterranean forests, woodland and scrub, and deserts and xeric shrublands. Wikipedia names them temperate, Mediterranean, tropical and desert. The tropical house is dense, hot and humid, according to RTBF, while the desert house is dry and arid. A pool recreates flooded tropical forests. Terrariums, kept by the non-profit Crusoé, house reptiles, amphibians and spiders.

The OMP presents about 3,000 species, subspecies and varieties. The official site cites a bryophyte collection unique in Belgium, plants from Madagascar and Namaqualand, orchids, myrmecophytes and carnivorous plants. The desert house, named Jean Doinet by a visitor's blog, holds more than 1,000 cacti and succulents. The tropical house brings together palms, bananas, screw pines, travellers' palms and tree ferns among others; RTBF cites there a nutmeg tree from Indonesia, a giant bamboo from China and a cacao tree.

The Mediterranean house gathers plants from four Mediterranean-climate regions, including holm and cork oaks, and holds the Minorca loosestrife, extinct in the wild and kept in cultivation. No pesticide or chemical fertiliser is used, and labels give the IUCN status of the species. Students of pharmacy, biology and veterinary medicine work there, and research collaborations exist with Oxford and Montpellier.

The complex is at Chemin de la Ferme 1, on the Sart-Tilman campus. The project manager quoted by RTBF describes a trip around the world of about an hour; the official site mentions guided visits. In summer the exhibition "Papillons en liberté", announced from 4 July to 25 October on the official site for the 2026 edition, lets about a hundred exotic butterflies fly among the plants, and a smartphone treasure hunt is offered in the OMP and the Sart-Tilman.

The visit can be completed with the Sart-Tilman botanical garden and arboretum, in the university forest, with its tree collection, shrub collection and aquatic-plant garden.