This beautiful long, low range of glasshouses is built of iron and has a distinctive, curved roof. This style and method of construction was promoted by the celebrated Dublin iron-master Richard Turner, and he was instrumental in having this range erected and was largely responsible for its design. In the 1990s it was fully restored by the Office Of Public Works, with particular care being taken to restore the building faithfully in all its facets.

The east wing was constructed in 1843 by William Clancy but the remaining sections were built by Richard Turner, and his son William. The two extreme wings originally had brick walls at the back (i.e. down the middle of the existing houses), but in 1869 their size was doubled by adding a matching half to the wings. This is the most important building in the National Botanic Gardens, and its central dome was featured for many years on Irish stamps.

The plant collections within the house have three main themes. In the Western wing is a collection of plants from the mountains of South-East Asia, in particular Vireya Rhododendrons (left).

In the Central House is a collection of Tender Gymnosperms, including some of Glasnevinís important cycad collection.

In the Eastern Wing are plants from the southern hemisphere, demonstrating the links between the Australian, South African and South American floras.