Victoriakas (Hortus Botanicus Leiden)

The Hortus Botanicus Leiden, founded by the university in 1590 and shaped by its first director Carolus Clusius, is the oldest surviving botanical garden in the Netherlands. Its first unheated glasshouse appeared around 1680, and the nineteenth century brought a proliferation of small specialist houses for orchids, ferns, palms and cacti.

It was in this setting that a house for the giant water lily, Victoria amazonica, was built in 1870–71. It was designed by Mr Schaap, superintendent of the university's buildings, to a brief drawn up by the head gardener and the professor. Topped with an ornamental cast-iron crown, it cost 4,300 guilders and soon drew the public; the first Victoria flower in Leiden opened in 1872.

Between 1936 and 1938 the glasshouses scattered around the garden were replaced by a single complex, and the historic house of 1870 was demolished. Today's Victoria House belongs to that 1930s ensemble. The complex underwent a major renovation from 2012, designed by the Leiden practice Veldman Rietbroek Smit; during the phased demolition, a tented enclosure was raised over the pond to keep the aquatic plants warm. Queen Máxima opened the renovated glasshouses on 4 September 2013.

The first Victoria House was a circular pavilion about 15 metres across and four metres high, carried on gracefully curved iron ribs and crowned with cast iron.

The 1936–38 complex followed a different logic: some twenty compartments of differing heights and temperatures, each with its own climate, arranged around a central Victoria pool with bevelled corners faced in natural stone. The house is raised to escape the shade of neighbouring buildings and catch as much light as possible, making it the warmest spot in the garden.

In the 2012–13 renovation the original steel trusses were kept along with their characteristic riveted joints, some of them heightened by new sections welded beneath. The work added steel walkways, stairs and a viewing platform, together with high-performance insulating glass and interior thermal screens.

The central pool is devoted to Victoria amazonica, the world's largest water lily, whose round leaves can reach three metres across according to the Hortus. Each flower opens for only two nights, white on the first and pink on the second. When a bud is about to open, a scent reminiscent of pineapple fills the house.

Around the giant lily grow many smaller aquatic plants, while hibiscus adds bright colour at the pool's edge. The Victoria House is part of the Hortus's tropical glasshouse sequence, which also displays orchids, giant aroids, carnivorous plants and ant plants.

The Hortus lies in the heart of Leiden's historic centre, along the Rapenburg canal, close to the university's older buildings. The Victoria House is reached along the route through the tropical glasshouses, which also includes the High Glasshouse and its walkway added in 2013.

The visit continues outdoors: the reconstruction of Clusius's garden, opened in 2009 from a sixteenth-century plant list; the Japanese garden dedicated to Philipp Franz von Siebold, inaugurated in 1990; and the monumental orangery of 1740–44, still used to overwinter tender potted plants.