It was built by Henry II of Trastámara as a means of defence against his brother Peter I (Peter the Cruel). It lies on what was once an Arabian castle.
It has a Latin cross plan with three arms formed by square towers joined by quarter cylinders and finished off with crenellations. It comprises of 8 rooms and houses the three cultures museum. It lies next to the Roman bridge and has been the site of many a battle. It houses the Museo Vivo de Al-Andalus (Al-Andalus Living Museum), by the Paradigma Cordoba Foundation.
https://www.spain.info/en/que-quieres/arte/monumentos/cordoba/torre_de_la_calahorra.html