Some of the numerous relics in the Temple of the Oath are located under the high altar, where the Eucharist is celebrated and, therefore, of sacred preeminence. There are the relics of Saint Columba, which arrived from Nájera (La Rioja) in 1737, the Holy Martyrs Liberatus, Magnus, Theodorus, and Urbanus, which came from the Royal Collegiate Church of San Hipólito in 1848, and Saint Fructuosus, donated by María Socorro Aguayo, widow marchioness of Lendínez (1855), as well as relics of martyrs of the XX century.