Jardin des Plantes, France. According to Edouard Fournier, Chronicles and Legends of the Streets of Paris (1864), Bernard de Jussieu (groundskeeper for King Louis XV) traveled to England in 1734 and “gifted” himself of two roots from a Lebanon Cedar tree, transporting the roots back to France in his hat (which he had transformed into a flower pot). The very first Lebanon Cedar roots were then planted on French soil, and thrived under Jussieu’s care. 
This story is disputed, however, by the naturalist Pierre Belon (1517-1564) who mentions the Cedar trees of France in his De Arboribus Coniferis (1553). More than likely, Jussieu’s trees are actually offsprings of the original cedars mentioned by Belon in 1553.