Castillo de los Vélez in Mula, Murcia, is a Renaissance fortress built around 1524 by Pedro Fajardo y Chacón, 1st Marquis of Los Vélez, on a rocky crag overlooking the town. Constructed on the site of an 8th-century Arab fortification that likely provided foundational materials and defensive structures, the castle represents a later overlay of Christian power over earlier Islamic defenses. The Renaissance-style architecture emphasizes defensive character with simple geometric forms, organized in four distinct sections including a Homage Tower, central nave with attached tower, and Cistern Tower. Though architecturally impressive, the fortress was built primarily as a symbol of the Marquis's power and control rather than for active military defense. Currently privately owned and closed to the public, the castle remains an important testament to Renaissance military architecture in Murcia.