Technology has made changes in communication, lifestyle, and cultures, creating a new challenge to heritage sites. Technology can be the answer to connecting with local communities and tourists, reducing the gap between people and their inheritance, making it more understandable, creating awareness and value and eliminating time and space limitations. It can be used to communicate, interpret, teach, analyze, and make heritage accessible. And it can also be applied to make virtual reconstructions of what no longer exists. This paper analyzes the effect of technology at a heritage site, using the Abbey of Cluny as a case. This Abbey is a monument in France due to its importance during the Middle Ages as the monastic capital of Europe. Today, there are only a few traces of what the Maior Ecclesia used to be. New technologies were applied to rebuild what was destroyed with time using augmented reality and 3D reconstruction. Qualitative methods were used to describe what effects in visitors and promotion of the site were observable.