Belfast Botanic Gardens has a long history of cultivation and display of ferns. The present Tropical Ravine began as a fernery known as the Tropical Glen, which was a replacement for a previous and smaller fern house, on the site of former orchid and propagating houses. 
The Fernery was an extraordinarily innovative venture by the then Curator of the Gardens, Charles McKimm, who built it with his gardening team. The following quote from the Belfast Newsletter, September 11th 1889, gives the flavour of this.

‘The new fernery, which has just been completed under the supervision of Mr. McKimm, by whom it was also designed and carried out in every detail – mechanical as well as botanical – will, we are inclined to think, come as a pleasant surprise to those of the public who have not been led by curiosity to investigate before now the secrets that lay hidden beyond the little door which might have been noticed in the wall at the end of the avenue opposite the bandstand. Few persons could have imagined that within the space of a few months the tiny fernery which Mr. McKimm built some years ago could grow into that wonderful landscape under glass which appeared last evening glowing beneath the subdued illumination of hundreds of Chinese lanterns and countless fairy lamps of all tints.
It is almost incredible that only seven months have elapsed since the work of planting this greenhouse was completed by the curator. From the luxuriance of the growth observable everywhere one might fancy that twice as many years had been needed to produce so marvellous effect. The directors of the Gardens are to be congratulated upon this addition to the attractiveness of their grounds We know of nothing of the same character in Ireland that is worthy of being compared with this fernhouse – indeed it may be safely said that no public garden in the United Kingdom possesses a fernery constructed upon so artistic a basis.’

Further praise appears in the same paper dated December 29th 1897, nine years later. The article describes a visit by a group of horticultural visitors from ‘Southern Counties’.

….. ‘We next turn to the fernery, which is the crowning glory of the Belfast botanics. It is nine years since it was built, and an extension of the house is now in contemplation. Of course, staging in this house is conspicuous by there being none. The idea is that of an undulating valley. The sides of the valley can also be traversed, little paths going up and around in the most natural way possible. At nearly every turn lovely views are presented, peeps which are quite chanting in this ever green vale. Noble tree ferns rise at intervals throughout the house from a base clothed with a verdure of dwarf-growing ferns. Conspicuous among the best of the tree ferns were – Dicksonia Antarctica, D. Squarosa, Cyathea Dealbata, Cibotium, Schiedei, Todea, Superba and Pellucida, are represented by capital pieces. Among the dwarf ferns growing in luxuriant health, planted out beside one of the paths, was a large clump of the ever-popular Killarney fern. It was the largest breadth of it most of the company had seen, and growing so freely without the usual codling of glass cases so often given to it, that Mr. McKimm was vigorously questioned as to how he obtained such success.’