On August 12, 1965, one of the most remarkable preservation projects in the history of the built environment entered a decisive phase in Nubia, southern Egypt, as work advanced to cut and relocate the ancient temples of Abu Simbel before rising waters from the Aswan High Dam could reach them. Carved directly into a mountainside in the thirteenth century BC during the reign of Pharaoh Ramesses II, the monumental temples had survived for more than three thousand years and had become among the most celebrated architectural remains of ancient Egypt. Their future was threatened in the twentieth century when construction of the Aswan High Dam was expected to raise water levels across a vast area of Nubia and create a huge reservoir, placing Abu Simbel and numerous other historic sites at risk of permanent submersion. Following appeals from Egypt and Sudan, UNESCO launched an international campaign in 1960 to save the endangered monuments. Engineers, archaeologists and construction specialists developed an extraordinary solution: the temples would be carefully cut into large stone sections, numbered, lifted to higher ground and reconstructed in their original architectural arrangement and orientation. August 12, 1965 marked an important stage in this complex cutting and relocation operation. Over the following years, the massive sections were moved and reassembled inside an artificial hill designed to reproduce the setting of the original site, with the Abu Simbel relocation completed in 1968. The wider Nubian preservation campaign ultimately involved the relocation of 22 monuments and architectural complexes and brought together specialists from countries across the world. The success of Abu Simbel demonstrated that major infrastructure and development projects did not necessarily have to result in the permanent loss of historic buildings and cultural landmarks. The campaign also helped strengthen the international idea that places of exceptional cultural importance form part of a shared human heritage, contributing to the development of the UNESCO World Heritage Convention adopted in 1972. August 12, 1965 therefore stands as a remarkable date in real estate and built environment history, when engineering was used not to erase the past in the name of development, but to physically move history so that it could survive into the future.