Willem-Alexander Pavilion (Keukenhof)

Keukenhof was founded in 1949 on the northern part of the estate of the same name at Lisse, on the initiative of the mayor, W.J.H. Lambooij, and around ten leading bulb growers who wanted a spring showcase for their trade. The park opened in 1950 under the landscape architect W. van der Lee, who remained its director until 1975. Glass soon followed: in 1951, with Easter falling early, a heated house of 2,025 m² was built to show 48,000 tulips in 750 varieties, and a cold house was added the next year. According to the local history society Oud Lisse, the name Willem-Alexander Pavilion covers the complex that grew out of those two original houses, adapted and renewed again and again.

The present building dates from 1996, when Smiemans Projecten put up a 6,200 m² arched glasshouse, one of the firm's very first HighLight glass structures and, by its own account, a concept never seen before. By then the park had added other pavilions named after members of the House of Orange: the Juliana in 1974, opened by Queen Juliana; the Beatrix, completed at the end of 1984, which from 1985 hosted weekly changing flower parades; and the Oranje Nassau in 1999, for the exhibition's fiftieth anniversary.

After renovation, the Willem-Alexander Pavilion was officially reopened on 13 April 2018. New Pilkington Profilit glazing was installed by D&O Bouwglas, with the building work carried out by the contractor Hoekstra & Hoekstra.

The pavilion is built for exhibition rather than cultivation and is the largest indoor space at Keukenhof, with more than 6,000 m² (6,200 m² according to its builder). It belongs to the family of HighLight arched glasshouses, whose glazing is designed to admit as much daylight as possible while sheltering plants from the weather. Under the high glass roof, white tension struts stiffen the structure, and shade blinds can be rolled across the glass to soften the sun.

Inside, timber screens divide the vast floor into a sequence of rooms, where plants are staged one at a time on plinths at knee and waist height, each with a card giving the cultivar and the grower. At the far end, timber pergolas shelter long wooden trays that feel more like a nursery than a gallery. The Profilit glazing fitted during the 2018 renovation was chosen, according to its manufacturer, for its high light transmission and versatile applications.

The pavilion has no permanent collection: displays are replaced throughout the eight-week season, so the building never looks the same for long. More than 500 tulip varieties are shown over a season, alongside massed amaryllis (Hippeastrum) in many colours, hydrangeas, hostas, gerberas, narcissi, daisies, trained pelargoniums and cut flowers, each presented under the name of the grower.

The climax comes late in the season, when the building hosts what the park bills as the largest lily show in the world: some 15,000 lilies in about 300 varieties across 6,000 m². The other pavilions each have their own theme: orchids fill the 1,000 m² of the Beatrix, the Oranje Nassau shows how flowers are used in interior design, and the Juliana houses the Tulpomania exhibition on the history of the tulip and the seventeenth-century speculative mania.

The pavilion stands in Keukenhof park at Lisse, which opens for only about eight weeks each spring. Across 32 hectares, more than seven million crocuses, daffodils, tulips, hyacinths, lilies and other bulbs flower outdoors; the pavilion offers shelter on rainy days and a close look at growers' new introductions. Lily lovers should aim for the end of the season, when the big show is staged. A visit combines naturally with the other pavilions, the park's windmill and Keukenhof Castle at the heart of the historic estate.