Sissinghurst Castle, UK

Before Sissinghurst, garden rooms were hardly a revolutionary concept. Gardeners had been carving up space with hedges, walls and carefully positioned doorways for centuries. But then along came Vita Sackville-West and Harold Nicolson and did something rather clever: they turned the idea into an art form. What appears at first glance to be a relatively modest Kentish garden unfolds as a sequence of distinct worlds, each with its own character, atmosphere and carefully orchestrated reveal. Visit in high summer and the planting steals the show. Visit in spring and something else becomes apparent. Stripped of its seasonal excesses, the underlying framework emerges – yew hedges, brick walls, borrowed views and sightlines all working quietly behind the scenes. From the ethereal calm of the White Garden to the dappled enchantment of the Nuttery, Sissinghurst remains a masterclass in enclosure, surprise and restraint. Not every idea has aged gracefully, but the central lesson endures: good gardens are about much more than plants.