This article considers the concept of the utopia from the point of view of garden design. It begins with an evocation of the `Jardin de Julie', the literary garden described in Rousseau and acutely analysed by Louis Marin. It then passes to a series of actual gardens created by the French contemporary designer Bernard Lassus, in which the use of landscape effects is seen as achieving similar dislocations of space and incitements to the imagination.