International Council on Monuments and Sites (ICOMOS), Second International Congress of Architects and Technicians of Historic Buildings

The Venice Charter codifies internationally accepted standards of conservation practice relating to architecture and sites. It sets forth principles of conservation based on the concept of authenticity and the importance of maintaining the historical and physical context of a site or building. The Venice Charter continues to be the most influential international conservation document. The Venice Charter states that monuments are to be conserved not only as works of art but also as historical evidence. It also sets down the principles of preservation, which relate to restoration of buildings with work from different periods.