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.

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.

[1] In 1825, they proposed an ambitious scheme for an open-ended residential square on Brighton seafront, the northern end of which would be occupied by "an oriental garden and a huge conservatory known as the Athenaeum".

[8] In 1832, Phillips was able to resurrect his idea for a large-scale conservatory, this time in Brighton's smaller but quickly growing residential neighbour Hove.

In 1830, Decimus Burton had begun work on Adelaide Crescent, a residential set-piece on the seafront, on land owned by Sir Isaac Goldsmid, 1st Baronet.

[2] Phillips had commissioned Amon Henry Wilds to design the structure and supervise the early work;[15] later he brought in C. Hollis as the chief engineer and a Mr English as the building contractor.

[10] The main cause of the "series of unfortunate accidents"[14] which the project turned into was the fact that no single person was in overall charge: Phillips, Goldsmid, Wilds, Hollis and English were not working as a team and concentrated only on their areas of responsibility.

[10] The immense ribs of iron snapped asunder in ten thousand pieces; and a great part of it, from the height it fell, was buried several feet deep in the earth.

A second much louder crack forced him to run outside and jump over a wall; the building, which weighed an estimated 400–500 tons, immediately collapsed and embedded itself in the ground.

Thomas Smith of Union Street in The Lanes, Brighton, was named as the glazier; he apparently reclaimed undamaged glass after the collapse and sold it at his workshop.

Sir Isaac Goldsmid was left "distraught" at the disaster, which may have contributed to his loss of enthusiasm for the residential development he was sponsoring at Adelaide Crescent immediately to the south.

[9] Prominent local architect Charles Busby attended a meeting at Brighton Town Hall some weeks after the collapse, at which proposals to rebuild the Anthaeum were discussed.