orchids. The soil at Glasnevin is strongly alkaline (in horticultural terms) and this restricts the cultivation of calcifuge plants such as rhododendrons to specially prepared areas. Nonetheless, the gardens display a range of outdoor "habitats" such as a rockery, herbaceous border, rose garden, bog garden and arboretum. A vegetable garden has also been established. The National Herbarium is also housed at the National Botanic Gardens. The museum collection contains some 20,000 samples of plant products, including fruits, seeds, wood, fibres, plant extracts and artefacts, collected over the garden's two-hundred-year history. The gardens contain noted and historically important collections of orchids. The newly restored Palm House houses many tropical and subtropical plants. In 2002, a new multistorey complex was built; it includes a cafe and a large lecture theatre. The gardens are also responsible for the arboretum at Kilmacurragh, County Wicklow, a centre noted for its conifers and calcifuges. This is located some south of Dublin. A gateway into Glasnevin Cemetery adjacent to the gardens was reopened in recent years. Architecture The gardens include some glasshouses of architectural importance, such as the Palm House and the Curvilinear Range. The Great Palm House is situated in the southern parts of the gardens, and is connected to the cactus house on its west side, and the orchid house on its east side. The main building measures 65 feet in height, 100 feet in length and 80 feet in width. The Palm House was originally built in 1862 to accommodate the ever increasing collection of plants from tropical areas that demanded more and more protected growing conditions. The construction was overseen by David Moore, the curator of the gardens at the time. The original structure was built of wood, and was unstable, leading to it being blown down by heavy gales in 1883, twenty one years later. Richard Turner, the great Dublin ironmaster, had already supplied an iron house to Belfast Gardens and he persuaded the Royal Dublin Society that such a house would be a better investment than a wooden house, and by 1883 construction had begun on a stronger iron structure. Fabrication of the structure took place in Paisley, Scotland, and shipped to Ireland in sections. By the early 2000s, the Palm House had fallen into a state of disrepair. After more than 100 years, the wrought iron, cast iron and timber construction had seriously deteriorated. Prior to its restoration a large