The history of urban design and urban planning is often conceptualized through a tension between top-down and bottom-up realizations of power. This binary is then mapped onto two ideal-type figures: the planner, with his privileged visuality from atop the skyscraper, and the flaneur, with his tactile and tactical routes through the streetscape. This article argues that the top-down/bottom-up dichotomy misses a fundamental location of power in spatial production: the mezzanine. The mezzanine is the strata of urban space located just above street level, but far below the perches of the planner’s eye. The article explores four mediations that occur on the mezzanine level: connectivity (utility poles, telephone wires, the grid), the management of mobility (traffic signs and signals), navigation (street signs, address systems), and surveillance (CCTV, street lights, eyes on the street). It argues that studies of material infrastructure located at the mezzanine complicate the top-down/bottom-up distinction.