HRA supported a project team led by Liz Sargent HLA and WJE to complete a historic structures report (HSR) for Castillo San Cristobal, part of the San Juan Historic Site, a complex of fortification dating back to the sixteenth century. HRA authored the historic context and contributed analysis of the character-defining features and preservation approach to inform the HSR, giving foundational guidance and planning for the National Park Service’s efforts to maintain the World Heritage Site for decades to come.