Pedra da Serpe is a unique monument of unknown origin and uncertain date. It is a granite rock with the relief of a snake, on which a cross was nailed. At the base of the transept we can see the figure of a winged serpent, something exceptional in the Western world.
In Galicia, representations of snakes date back to the megalithic period, with some engravings appearing in dolmens. The motif of the snake is also present in some petroglyphs and in some sites of the forts. The figurative relief, like that of this stone, only appears after the Romanization.
Legend has it that it was Saint Adrian, patron saint of this parish, who freed this land from a plague of snakes, by hitting them hard with his foot on the ground and making them all disappear, leaving them enchanted under this stone.