According to the Jacobean tradition, the Pedrón is where the boat was moored that transported the remains of St. James from Palestine to the Galician coast and was accompanied by his disciples Theodore and Athanasius.

This very important object related to the worship of St. James can be seen below the main altar of the Church of Santiago, in Padrón, which was erected beside the Sar River in the year 1133 by Archbishop Xelmírez.

Although the Pedrón is really a Roman altar from an undetermined period, whose inscription, located in the front of the monument, is translated by some authors as “To Neptune, the forum of Iria with your money.”