Hierro Castle, locally known as Castillo de Hierro or Castillo de Pruna, lies on a small mountain next to the village of Pruna in the province of Sevilla in Spain.
The site where Hierro Castle now stands was first used by a local Celtiberian tribe called the Turduli. They founded a small settlement here named Callet. Later on, it became one of the first Roman encampments in the area during the continuous battles for domination of Hispania.
Probably during the 12th century or the beginning of the 13th century, the Moors built a watchtower on the mountain. Probably in the 13th century they turned the tower into a small castle by reinforcing it with a small parapet to defend it against attacks from Castilian troops. Under Moorish ownership the site around the castle was used as a farmstead.
During the time of the Reconquest, Hierro Castle was situated in an area known as the Moorish Strip; a kind of no-mans land which formed the border between the Emirate of Granada and the Kingdom of Castile. In 1248 the castle was taken for the first time by the Castilians. From then on it was taken and re-taken by the Moors and the Castilians several times. In 1256 the castle was given to the military Order of Calatrava by Alfons X, King of Castile. In 1407 it was definitively conquered by the Kingdom of Castile.
When I visited Hierro Castle, it was in the process of being 'restored' in that widely spread ugly Spanish restoration practice of rebuilding wall parts with a sort of concrete. It really robs the ruin of its character. Just search the internet for pictures and you will see what a beautiful ruin it once was.
Hierro Castle is freely accessible. To get to the castle you will have to make a strenuous 25 minutes walk uphill. The views from the top over the surrounding countryside a fabulous and you can easily see Olvera Castle to the south.