One method of study available to the geographer is to penetrate the invisible, the hidden, through the visible. The very nature of homosexuality renders research into gay spaces difficult to consider outside mediatic, fantasized or decried spaces like the Marais. Beyond that, one may debate on the form(s) visible in the Marais, on what is accessible to the untrained eye. Hence the question: what gives form? But also: who sees what ? Would a space visible to an actor be visible to all ? Through gay spaces, the geographer interrogates perception, and the representation of spatial forms.