This study examines the concept of "urban archaeological accumulation" as a complementary approach to traditional object-oriented conservation. It argues that cities accumulate irregularly over time through uncontrolled stratification, challenging the conventional view of historical contexts as orderly compositions of objects. The paper analyzes the concepts of accumulation, stratification, objects, and voids through theoretical frameworks, conservation laws and regulations, and case studies of three urban voids in Istanbul - an open cistern, urban square, and ancient harbor. It ultimately discusses how cities accumulate and what intellectual tools are needed to conserve this irregular accumulation as an alternative to merely ordering and articulating historical objects.