The Castle of Castellcir, also known as the Castle of the Popa, is located in the Serrat de la Popa, within the municipality of Castellcir.
The first documentary mention we have of this castle dates back to 1014. The castle is located on a rocky spur of the Sauva Negra massif, and its function was to defend and control the valley of the Castellcir stream.
The castle of Castellcir remained in good condition until the beginning of the 20th century, as it was converted into a farmhouse after it lost its military functions.
From the castle we can still see the remains of the wall, as well as the remains of the main building. In addition, the remains of a two-storey building in the central part are still preserved. These remains would have been part of the farmhouse until the beginning of the 20th century.
There is only one access point to the castle, located in a linteled portal with a semicircular arch. From this room, we can visit the two wings of the platform where it is located.
From this point, we can also enjoy magnificent views of the municipality of Castellcir.
A legend has also been preserved in this castle. According to the legend, from the Popa Castle there was an underground passage that linked it with the Moorish Tower (located at the foot of the castle). Apparently, a golden lamb is buried in this tunnel. Many curious people tried to look for the golden lamb, but every time they entered the tunnel, the torches went out. After some time, seeing that it was impossible for them to find the golden lamb, they decided to cover up the tunnel, as many pigs and lambs were lost.