TerraCool is a passive cooling system that combats extreme heat in urban areas. It uses Ceramic Evaporative Cooling (CEC) technology, harnessing terracotta's properties to create comfortable thermal environments with lower energy consumption. Fired terracotta's porous nature allows water to permeate and evaporate on the surface, cooling the air through phase change. TerraCool's design maximises surface area and efficiency via minimal geometries and parametric principles. Customisable units can be created based on local climate conditions, allowing bespoke solutions. TerraCool is scalable and cost-effective, using slip-casting and widely available materials. It can be used indoors and outdoors and as a self-sufficient system in urban parks. TerraCool aims to promote CEC and energy-efficient urban environments while combatting urban heat islands.