Chelsea Physic Garden. London, UK.
"The Chelsea Physic Garden was founded in 1673, as the Apothecaries’ Garden, with the purpose of training apprentices in identifying plants. The location was chosen as the proximity to the river created a warmer microclimate allowing the survival of many non-native plants – such as the largest outdoor fruiting olive tree in Britain – and more importantly, to allow plants to survive harsh British winters." Source: Garden website.