This document describes assessments recommended for in situ preservation and monitoring of archaeological sites. It sets out the main parameters used to assess the state of preservation of archaeological materials and evaluate the environmental conditions of archaeological deposits and provides a framework for monitoring sites. A decision-making framework is included to help readers make appropriate knowledge-based choices. The procedures described are appropriate for terrestrial, wetland or underwater archaeological sites. They will not necessarily be relevant to all archaeological sites, and the level of assessment required and the resources needed are expected to be balanced with and proportionate to the significance and complexity of the site and the scale of any proposed changes. The informative annexes relate primarily to terrestrial sites; for detailed technical guidance on investigating and monitoring underwater sites, see sasmap.eu. NOTE Underwater sites include all underwater sites and those in the intertidal zone.