The Anthaeum was an iron and glass conservatory planned by English botanist and landscape gardener Henry Phillips and designed by architect Amon Henry Wilds on land owned by Sir Isaac Goldsmid in Hove, a Sussex seaside town which is now part of the city of Brighton and Hove. Conceived on a grand scale and consisting of a gigantic cupola-topped dome covering more than 1.5 acres (0.61 ha), the structure was intended to enclose a carefully landscaped tropical garden, with exotic trees and shrubs, lakes, rockeries and other attractions. The scheme was a larger and more ambitious version of a project Phillips and Wilds had worked on in 1825 in Hove's larger neighbour Brighton, for which money had run out before work could commence. Unlike its predecessor, the Anthaeum was built: work began in 1832 and an opening ceremony was planned for 31 August 1833. Disagreements between the architect, the project engineer and the building contractor led to structural problems being overlooked or ignored, though, and the day before it opened the Anthaeum collapsed spectacularly. Its wreckage stayed for nearly 20 years overlooking Adelaide Crescent, a seafront residential set-piece whose northern side it adjoined, and Phillips went blind from the shock of watching the largest of his many projects end in disaster. Palmeira Square, another residential development, has occupied the site since the late 19th century.

A conservatory is a building or room having glass or other transparent roofing and walls, used as a greenhouse or a sunroom. Usually it refers to a space attached to a conventional building such as a house, especially in the United Kingdom. Elsewhere, especially in America, it can often refer to a large freestanding glass-walled building in a botanic garden or park, sometimes also called a palm house if tall enough for trees. Municipal conservatories became popular in the early 19th century.