El Real de la Jara enjoyed a strategic position throughout the Middle Ages, which made it a major defensive hub, as evidenced by the remains of the Castle, located a stone's throw from the town.
The castle stands on a high hill to the north of the town.
The building has a trapezoidal shape and has two doorways and eight towers, three of which are semicircular. The main door is curved and is located in the keep, to the south of the building. The secondary door is on the opposite side. Both doors have been completely rebuilt with granite masonry.
In the southeast corner there is a tower with a chamber, which interrupts the passage of the battlement walkway and from which the main entrance would be defended. In the northeast corner there is another square tower, which has been restored in such a way that it is impossible to know whether it also had a chamber. On the wall that joins them there is a semicircular apse, possibly added to its construction at a later date.
In the northwest corner of the northern wall there is another tower, also fully restored, making impossible to know whether it had a chamber. Between the two, and as on the eastern wall, there is another semicircular apse.
The keep, which interrupts the passage of the battlement walkway, has a large chamber with a barrel vault and a staircase leading to the roof. There is no evidence of the existence of a machicolation to defend the door, since the upper half of the tower has been completely rebuilt, but it must almost certainly have existed. Currently, there are no cisterns in the courtyard, but it can be assumed that there must be at least one, although it must be concealed.
The entire building is made of 2.2-metre-thick masonry walls, filled with earth and stone. There are no putlog holes inside the walls since, before they were restored, the walls were half as high as they are today, but in the castle's wide parade ground of almost 2,000 square metres there must have been the rooms typical of this type of building: stables, storerooms, lodgings for the troops, etc.