Triangular Hillfort of Castilviejo de Guijosa

Castilviejo de Guijosa is an ancient hillfort located in the municipality of Sigüenza, Guadalajara, Spain. It's built on a hill composed of Triassic calizas and appears in the shape of an isosceles triangle. The wall is divided into five sections, with the northern section having an access gate without special protection. The southern section boasts a thirteen-meter-long, six-meter-wide tower. The walls are formed by a double row of carefully worked stones, especially on the exterior.

The area between the two rows is filled with stones of different sizes. The hillfort features a defense system consisting of two groups of chevaux de frise, which are arranged in a regular manner and end at the edge of the cortado, making it impossible to access the settlement without passing through a four-meter-wide passage. The area inside the fort is very ruined, with few surviving remains, suggesting that the houses were of a quadrangular shape.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons