Infinity is a visual and sound installation which invites the user to enter into an infinite space. People can look through an opening and experience the echo of their own voice while seeing themselves in an inﬁnite reflexion. The openings are positioned at different heights, allowing children and adults to interact freely inside the structure. Built out of duplicated cardboard modules linked by elastic ropes, the construction offers a maximum of effects with a minimum of means. It is efficient to produce, stackable in piles for transport, it can be quickly built in different kinds of shapes without the help of tools and is therefore inexpensive.