<p>Spanish cultural heritage continues to play a role in social, cultural, and political developments in Micronesia and can contribute to a broader understanding of Indigenous and Spanish histories in the Pacific. Thus, Spanish cultural heritage should be appropriately identified and incorporated into a cultural heritage management and research framework for the Commonwealth of the Northern Mariana Islands (CNMI). Unfortunately, this is not the case, and this heritage is long overdue for serious investigation and research in the CNMI. This paper describes a project related to the potential for research on Spanish cultural heritage on land and underwater in the CNMI. The project aimed at facilitating the process of documenting Spanish cultural heritage by identifying known and potential heritage recorded in disparate sources such as grey literature, primary and secondary historical sources, archive and museum holdings, conversations with heritage practitioners, and oral histories. The methodology used for the survey included a thematic assessment framework whereby the known and potential Spanish cultural heritage was categorized into research themes. One theme “Maritime Spheres” was expanded to include a review of the Manila galleon trade, and the shipwrecks located in the CNMI resulting from this long-distance route. The history of the galleons, their contemporary salvage, their modern salvage, and their potential for future research are outlined. It is hoped that this paper will contribute to the growing knowledge of this significant period of history in the Mariana Islands and assist with evaluating the significance of Spanish cultural heritage for research and management purposes in the CNMI.</p>