The National Botanic Gardens (Irish: Garraithe Náisiúnta na Lus) is a botanical garden in Glasnevin, 5 km north-west of Dublin city centre, Ireland. The 19.5 hectares are situated between Glasnevin Cemetery and the River Tolka where it forms part of the river's floodplain. The gardens were founded in 1795 by the Dublin Society (later the Royal Dublin Society) and are today in State ownership through the Office of Public Works. They house approximately 20,000 living plants and many millions of dried plant specimens. There are several architecturally notable greenhouses. The Glasnevin site is the headquarters of the National Botanic Gardens of Ireland which has a satellite garden and arboretum at Kilmacurragh in County Wicklow. The gardens participate in national and international initiatives for biodiversity conservation and sustainable development. Director of the Gardens Dr. Matthew Jebb, is also Chairman of PlantNetwork: The Plant Collections Network of Britain and Ireland. It is Ireland's seventh most visited attraction, and the second most visited free attraction. History Poet Thomas Tickell owned a house and small estate in Glasnevin and, in 1795, they were sold to the Irish Parliament and given to the Royal Dublin Society for them to establish Ireland's first botanic gardens. A double line of yew trees, known as "Addison's Walk" survives from this period. The original function of the gardens was to advance knowledge of plants for agricultural, medicinal and dyeing purposes. The gardens were the first location in Ireland where the infection responsible for the 1845–1847 Great Famine was identified. Throughout the famine, research to stop the infection was undertaken at the gardens. Walter Wade and John Underwood, the first Director and Superintendent respectively, executed the layout of the gardens, but, when Wade died in 1825, they declined for some years. From 1834, Director Ninian Nivan brought new life into the gardens, performing some redesign. This programme of change and development continued with the following Directors into the late 1960s. The gardens were placed into government care in 1877. In the winter of 1948/9 Ludwig Wittgenstein lived and worked in Ireland. He frequently came to the Palm House to sit and write. There is a plaque commemorating him on the steps he sat on. Facilities As well as being a tourist destination and an amenity for nearby residents, the gardens – offering free entry – serve as a centre for horticultural research and training, including the breeding of many prized