The Palm House. Built between 1844 and 1848, this victorian iron structure was designed to be a scientific, hi-tech research laboratory for palm trees, from which we get all sorts of useful crops, textiles, gums and other chemicals. The Royal Botanic Gardens, Kew, usually referred to simply as Kew Gardens, are 121 hectares of gardens and botanical glasshouses between Richmond and Kew in southwest London, England. It is an internationally important botanical research and education institution with 700 staff, receiving around 2 million visitors per year.