San Juan de Ulúa (Fortress of San Juan de Ulúa)

San Juan de Ulúa is identified in the provided sources as a fortress complex situated on an island overlooking the port city of Veracruz. The archive cartographic record ('Plano del puerto de Veracruz') includes a large inset titled "Plano de la ciudad y plaza de la Veracruz, y castillo de San Juan de Ulua," situating the fort within the harbor layout and indicating its maritime and defensive significance. The map shows the harbor with islands, sandbars, and soundings and highlights the part of the harbor containing the fort, evidence of the site's prominence in historical urban and naval planning. The supplied sources are limited to an encyclopedic identification (Wikipedia) and the descriptive record of a historical harbor map (archive catalog). They do not provide construction dates, detailed chronology, accounts of specific historical events, contemporary access status, or any folkloric or supernatural narratives connected to the site. No named entities or hauntings are described in the provided material. Further archival, historical, and folkloric research would be required to expand the site's history and any cultural narratives beyond the cartographic and identification statements in the available sources.