This paper presents the results of an advanced analysis and dynamic monitoring of the historic bell tower of St. Nicholas Cathedral in Newcastle Upon Tyne. The study includes a detailed examination of the tower’s geometry, masonry condition, morphology, and overall structural stability. Completed in 1474, the bell tower is a Grade I listed structure of significant historical and architectural importance. Rising 61.24 m from its base (12.03 × 11.99 m) to the steeple’s peak, the tower is constructed of finely-cut sandstone blocks bonded with lime-based mortar. These blocks are supported by four stonemasonry pillars, which are subject to high compressive stresses. The analysis also explores the tower’s historic construction phases and evaluates their implications for its structural behavior. Key findings highlight the critical role of wall-to-wall connections and the modifications in stonemasonry techniques observed during repair efforts. Particular attention is given to subsidence and settlement mitigation measures applied to the east face of the tower. Additionally, further analyses were conducted to assess the structural behavior of this iconic stonemasonry landmark.