In 737, King Favila built a chapel on a primitive dolmen to house the wooden cross that Pelayo raised at the Battle of Covadonga and which later became the Victory Cross. It is further believed that this was the first Christian church to be built in Asturias after the retaking of Spain from the Moors. The dolmen structure is formed by five large slabs of stone and two smaller ones forming a rectangle. The inner chamber was covered by a large mound of boulders and stones. The slab we see today is a modern tombstone.
Limestone, sandstone and quartzite were used in the construction of the blocks. The inner faces of the dolmen have engravings, paintings and pitting.
The chapel, which houses the dolmen, is newly built in keeping with the stylistic canons of the area. It is rectangular and divided into two parts, chapel and porch. The porch includes the access stairway. The porch roof is supported by a Tuscan column and a wall topped with a bell gable.
The walls of the nave are reinforced with two buttresses and there is a niche window that illuminates the interior.
The chapel is covered with barrel vaulting.
A plaque placed on the wall recalls the old inscription regarding King Favila. The dolmen is visible from the centre of the chapel.