If there is a fortress in Mula that leave you speechless is Alcalá castle. It is 120 metres above the village and you can see all the town from there.
To get there , you have to take a path you find in the road from Mula to Murcia ( kilometre 22) where Librilla road starts.
It is a islamic fortress and one of the oldest in the Region. It was founded in the VIII century when Muslim troops stablished there to control the old Mula settlement. Mula was one of the seven Tudmir towns.