Spreading out on 8 hectares (20 acres) at the edge of the River Vartry, this peaceful and romantic site was once an ancient lake. Since 1868 it’s been a riverside garden, designed in a distinctively informal style, with fiery rhododendrons, fragrant eucalyptus trees, giant Tibetan lilies, and snowy camellias competing for your attention. Attuned to their natural setting, these gardens have an almost untended feel—a sort of floral woodland. A spacious cafe, run by the fantastic Avoca chain, overlooks the river and gardens. The courtyard at the garden entrance contains an interesting assortment of shops selling seeds, gardening supplies, and books.