The castle of Santa Catalina is an old defensive construction with a Christian-medieval finish, which crowns the hill of the same name, on a foothill of the Sierra de Jabalcuz at 820 m altitude, from which the entire city of Jaén can be seen, the olive groves and the surrounding mountains in the area.

The name comes from the chapel that would be built in the castle after its conquest. The Chapel of Santa Catalina de Alejandría is in the Gothic style, and was built between the 13th and 14th centuries.

This enclosure, also called Castillo or Alcázar Nuevo, sits on the living rock of the hill, and is one of the three defensive enclosures that make up the Castle of Jaén. On its west side, the Torre del Homenaje is located, which, in other times, served as a backbone with the old fortress. It is a large tower with a square plan, 15 m on each side, and more than 30 m high, with three floors and a terrace, with crossed vaults with pointed arches, and access from the parade ground.

The entire southern perimeter lacks towers, as it is built on a vertical escarpment. There is in this cloth, a postern and a projection, which houses a latrine. On the other hand, on its northern perimeter there are three towers, two of them albarranas and a third, next to the access door. Finally, there is a fifth tower, pentagonal, at the eastern end of the enclosure.

The parade ground is large, and it contains the remains of various constructions, including two wells and a bastion.

All the facing of this castle responds to a new architectural type, in relation to the existing fortress: small masonry in the general work, ashlar or ashlar in the corners, and brick or stone voussoirs in the arches.