A pioneering work by Brazilian Concrete artist Lygia Clark, *Unidade I* explores the tension between geometric form and spatial perception through precise, structured composition. The work reflects Clark's early engagement with Concrete art principles, investigating how line, plane, and surface interact to challenge the boundaries between the artwork and the space it inhabits. It stands as an early milestone in her evolving inquiry into the relationship between the object, the viewer, and the lived experience of form.