The Dolmen of Arca
Arca can be very proud of having one of the symbols of the megalithic culture of the Oliveira de Frades municipality and of all the Serra do Caramulo: the widely known dolmen of Arca.
This monument consists of three blocks in an approximately vertical position (pillars), with some others now broken, on which rests a large capstone (or table) covering the interior area. It measures about 4.5 meters high and the table is 4.20 by 3.20 meters.
Like other dolmen constructions, it must have had an access corridor and a circular mound of earth and gravel that served as protection, which is called a tumulus.
About the dolmen of Arca, a national monument by decree dated 16th of June 1910, says Dr. Amorim Girão: "by intending to enumerate these monuments, the first place rightfully belongs to the dolmen located not far from the main church of the Holy Spirit of Arca, as it is the one with the largest external dimensions of all of them, since, being the only one that is widely known, it has been used to authenticate numerous reports or references that have been written about the late antiquity to which human settlement in this region dates back.
(…) Many references have been made to this important megalithic monument, known and designated on the Corographical Chart by the name of Pedra de Arca (Boulder of Arca) - which names some settlements, like Arca, Paranho de Arca, And Covelo de Arca.
Despite its dimensions not being far greater than those of its nearby counterparts, the fact that its tumulus has been destroyed, which it most definitely possessed at one point, leads to there being a 4.5 meter distance from the ground to the capstone, which allowed horses to pass below and it also prevented people to climb it without the help of a ladder, grants it first place among the megaliths of the region".
Many legends are told regarding this dolmen, with the most popular among them being the tale of the Moorish woman According to this tale, the dolmen was erected by a Moorish woman, with the capstone sat on top the pillars being placed by her, carrying it on her head, spinning on a distaff and a child on her arms.
The Moor appears every year at dawn on S. João spinning flax on top of the dolmen and surrounded by gold objects; the lucky mortal who passes through there first will be asked which one he likes best: the eyes of the Moorish woman or the gold objects she has there. As all have said they like the gold objects best, they have always turned to ashes due to the Moorish woman's magical powers. They will only get the gold objects when they are more pleased with the eyes of the Moorish woman rather than the gold.