Arjona was defended by one of the most complex fortified castles in Spain. The imposing ruins of the fortification are still preserved on the avenue known as the Paseo de los Mártires, where sections of the wall and the curtain wall that protected it can be seen. The medieval defences comprised an outer walled enclosure that was more than two kilometres long, surrounding the town, and a fortress or fortified neighbourhood at the highest point, located in what is now Santa María square.

That is precisely where to start a tour of the town. The square is located at the highest point of the town and affords stunning views of the Jaén countryside. A spectacular medieval cistern, possibly Almohad, still exists next to the church, in the spot where it is believed that an aljamaor Moorish mosque was built. The cistern was restored some years ago. Inside, you can see a video that takes the cistern as a point of reference to tell the story of Arjona, the first Copper and Bronze Age settlements, its outstanding role as an Iberian oppidum, and its relevance as Urgavo, or Urgao Alba, one of the countryside’s main Roman cities.

Next to the cistern, hidden in courtyards and among the adjacent houses, some of the towers and remains of the old fortress walls can be spotted. Curiously, the castle and fortress of Arjona underwent a huge transformation in the 17th century when the relics of martyrs San Bonoso and San Maximiano were found. To find them, some of the oldest archaeological excavations in Spain were conducted in the square. The work uncovered the bases of a Roman temple and an Argaric necropolis with tombs that were identified as the relics of numerous Christian martyrs killed during the persecution of Diocletian. Among them were two Roman centurions who have been the patrons of Arjona since then.

A stroll through Arjona reveals other charming spots to travellers, such as the Jewish quarter, which is also close to the location of the old castle. It is one of the few examples of Jewish architecture that is preserved in Jaén province.