During ancient and medieval times, the space of the Zarautz Jauregia had to be adapted to the needs of the inhabitants, especially in the area near Kale Nagusia, where a river, now channelled, flowed into the valley.

In the late Middle Ages, a plot of land was created which in the 15th century belonged to the Zarauz family. This tower was made up of a rectangular tower house with some spaces dedicated to craft and storage uses, and others related to leisure activities and social representation. All these elements are enclosed by a wall.