Palacio de Cristal de la Arganzuela (greenhouse)

The building belongs to the former Matadero y Mercado Municipal de Ganados, a vast complex of some 16.5 hectares designed by the municipal architect Luis Bellido y González in a Neo-Mudéjar style, beside the Manzanares. Sources disagree on the dates of construction: 1908 to 1924, 1910 to 1925 or 1908 to 1928. Very modern for its time, the complex ended up engulfed by the city; it closed progressively from the 1970s and 1980s, and one source places the final closure in 1996. The hall where potatoes were stored, nicknamed the Nave de Patatas, then stood unused.

In 1992 the city council decided to convert it. The project, attributed by Wikipedia to the designer Guillermo Costa Pérez-Herrero, kept the riveted steel frame and replaced opaque materials with translucent panels, adding a climate-control system. The greenhouse was inaugurated on 21 December 1992 by Mayor José María Álvarez del Manzano. It now stands near the cultural spaces of the Matadero and Madrid Río, the linear park that runs along the river.

The hall is a rectangular volume carried by a riveted steel frame, whose conversion replaced solid walls with translucent panels. The whole covers about 7,100 m², organised in five parts: a central crossing of about 2,300 m² and four rectangular spaces of 1,200 m² each, laid out as a cross.

Each of the four spaces is enclosed to form a distinct microclimate: two tropical zones, one subtropical zone and one desert zone. Glazed doors separate them to preserve their temperature and humidity. Fountains, small pools and resting areas punctuate the route. The steel frame, presented by the city as one of the few surviving examples of iron architecture in Madrid, gives the whole the air of a Victorian greenhouse despite its utilitarian origin.

The place presents itself as a botanical museum of more than 9,000 species divided among four zones. The desert zone gathers cacti, succulents and aloes adapted to drought, notably the golden barrel cactus (Echinocactus grusonii). The subtropical zone shows dense vegetation that tolerates temperature swings. Fan palms, Canary Island date palms and dragon trees are among the most notable species of the whole.

The two tropical zones are more humid and show epiphytes, lianas and aquatic plants around pools and fountains. Together they illustrate how plants adapt to the main climate types. A former dahlia garden nearby, with more than 3,000 plants, was redistributed to the Real Jardín Botánico and to the Dalieda de San Francisco.

The greenhouse stands on Paseo de la Chopera in the Arganzuela district, near Legazpi metro station, close to the Matadero Madrid cultural centre and the Madrid Río park. It is municipal and free to enter; allow about an hour to cross the central crossing and the four zones, starting with either the tropical or the desert zone depending on the direction of circulation. The gardens and playgrounds around it make it an easy stop on a walk along the Manzanares, to be combined with the rest of the Matadero and the landscaped riverbank.