The architectural and archaeological landscapes of Sri Lanka (referred to as Ceylon during the colonial period) is renowned for its historical and cultural richness, exemplified by ancient cities, such as Anuradhapura, Sigiriya, and Polonnaruwa, which date back to the second century BCE. These cities, long buried, were rediscovered in the mid-nineteenth century through the interventions of colonial administrators and professionals employed by the British Ceylon Government (1806-1948). The uncovering of the ruins of these ancient cities, mainly Buddhist monastic complexes, significantly contributed to their eventual recognition as UNESCO World Heritage Sites. Against this background, this essay narrates the inception and development of systematic architectural and archaeological documentation practices during Sri Lanka’s colonial period, focusing on the pioneers who laid the foundation for this enduring legacy. The study draws from archival, cartographical, and iconographical research to critically examine the first instances of colonial architectural and archaeological documentation. The findings reveal that the early British efforts evolved into a comprehensive and systematic exploration of Sri Lanka’s ancient heritage, culminating in the establishment of the Archaeological Survey of Ceylon.