The castellum at Maastricht raises important questions about the late Roman reorganisation of the frontier in this region, especially under Constantine I and his successors. Dendrochronology, building history and comparative studies suggest a major rebuilding phase around the early 4th century, when massive new walls, towers and gates were constructed to enclose and protect the former civilian settlement. Yet many aspects of this programme remain debated.
Key open questions include the precise date and sequence of construction events, the relationship between the fort and the former civilian settlement, and the size and composition of the garrison stationed to protect the Meuse crossing and this leg of the Via Belgica. The role of Maastricht within broader defence and supply networks along the Meuse and Rhine—whether as a primarily military strongpoint, a logistical hub, or a mixed civic‑military centre—also continues to be explored.
The 3D reconstruction does not claim to settle these debates. Instead, it visualises one set of possibilities grounded in current scholarship, making complex spatial and architectural problems easier to grasp for both specialists and the public. As new excavations, material analyses and historical studies refine our understanding, the digital model can be revised, annotated and expanded, reflecting the evolving state of research.