Kew Gardens lie on the opposite side of the Thames from Syon House. Kew Park was enlarged and embellished by Augusta, Dowager Princess of Wales from 1759, when the arch was built 'to make a passage for carriages and cattle, over one of the principal walks of the garden' [and] 'to imitate antiquity'. (W. Chambers, 'A Description of the Palace and Gardens at Kew, the seat of the Princess Dowager of Wales', Royal Magazine, September 1763, p. 154).