Great Tropical Greenhouse of Parc Phœnix ("Green Diamond")

Parc Phœnix was inaugurated on 14 February 1990 after twenty-six months of works involving nearly eighty companies. The site, former marshland in the Arénas district beside the Promenade des Anglais, belongs to the City of Nice. The park's own history page names Monsieur Aragon as architect and Monsieur Arnaudon for the landscape design; the PSS architecture database gives the architect's first name as Jean-Claude (a Nice architect, 1927-2015). The park takes its name from Phoenix canariensis, the most widespread palm on the Côte d'Azur.

Sources disagree on the cost: Wikipedia, citing the press of the time, gives 308 million francs (47 million euros), while the park's website mentions 260 million francs (about 40 million euros). The works required moving 14,000 m³ of earth and 2,000 tonnes of rock to shape the site.

Conceived first as a botanical garden, the park later added animals (lemurs, otters, wallabies, macaws). It received the "Jardin remarquable" label in 2011, renewed in 2016, and welcomes about 350,000 visitors a year according to the figure cited for 2024.

The greenhouse is a volume close to 100 metres in diameter and 25 metres high, covering about 7,000 m² of floor. Its glass roof amounts to roughly 10,000 m² of glazing and spans the space without intermediate supports, which is why it is described as one of Europe's largest single-span greenhouses. It has carried the nickname "Green Diamond" since its construction.

The interior is divided into distinct climatic spaces regulated by computer. Sources differ on their number: six according to the official website and PSS, seven according to Wikipedia. The official site describes a central humid tropical zone, two southern African zones (dry and humid) and a fern house. The central zone is kept at a minimum of 16 °C in winter and about 80% humidity, with high-pressure misting using osmosed water. At the centre, a rotunda is decorated with pre-Columbian-style ruins.

The greenhouse shelters about fifty palm species, among them coconut, traveller's palm and white Bismarck palm, together with pandanus, pothos, frangipani and Caribbean heliconias. Orchids are prominent (vanda, dendrobium, phalaenopsis, paphiopedilum, oncidium) alongside bromeliads, aroids, carnivorous plants, bananas and figs.

The fern house gathers tree ferns from Africa and Australia and epiphytic ferns of the genus Platycerium. The dry and humid southern African zones recreate habitats of the Karoo, Transvaal, Natal and Cape Province, with aloes, euphorbias, stapelias and lithops. The animals include Nile crocodiles, spectacled caimans, iguanas and Chilean flamingos, as well as underground aquariums and terrariums with tropical fish, insects, myriapods and arachnids.

The greenhouse stands at the heart of Parc Phœnix, a seven-hectare site in the Arénas district along the Promenade des Anglais, on the western side of Nice. Half a day is a reasonable allowance for combining the greenhouse with the rest of the park, which has some twenty themed areas: a central 3,500 m² pond with pelicans, swans and turtles, Mediterranean gardens and animal collections. The warm, humid atmosphere of the glasshouse contrasts strongly with the outdoor climate in winter, which makes it a pleasant visit in that season. The seafront walk along the Promenade des Anglais is a natural extension of the outing.