Pyramid Glasshouse (Tropical Centre)

Opened in 1972, the Royal Botanic Garden Sydney's Tropical Centre paired a glass pyramid with a curved glasshouse called the "Arc" to display the city's tropical and desert flora. Increasingly costly to maintain and limited by its low interior height, which prevented the growing of large trees, the pyramid eventually closed to the public and was demolished in the mid-2010s, leaving the site derelict and overgrown for a time. It was replaced by The Calyx, a new horticultural pavilion opened in June 2016 for the garden's bicentenary, while the Arc's structure was partly preserved and incorporated into the new building. Its disappearance illustrates the fate of many 1970s modernist greenhouses, judged obsolete in climatic and energy terms. The pyramid nonetheless remains an important milestone in the garden's architectural history, today documented only through archival photographs.