4. Pedra da Arca
It is located in the parish of Baíñas. Its walls still have traces of engravings consisting of U- and V-shaped lines (+43° 2' 5 "-9° 1' 42").
There are also traces of red paint.
It is one of the largest antas (dolmens) in Galicia, both for the volume of its stones and for the diameter of the tumulus it rests on, measuring 92 feet wide and 98 feet long, with the capstone alone weighing 12 tons.