The Chapel of San Isidro is located in an area known as the fields of Carabanchel, lands that once belonged to Juan de Vargas, the landowner who employed San Isidro as a well-digger and farm labourer. It stands beside the spring which, according to legend, the saint miraculously caused to flow to quench his master’s thirst—a spring to which popular tradition attributes healing properties.
There is no surviving documentation to confirm the exact date of construction of the first chapel, but the earliest evidence of its existence appears in 1499, in ecclesiastical visitation records preserved at the parish of San Andrés.
In 1528, Empress Isabel of Portugal, wife of Emperor Charles V, ordered the construction of a new sanctuary beside the spring in honour of Saint Isidore, in gratitude for the recovery of the emperor and their son, Prince Philip—later King Philip II—after drinking from its waters.
Later, in 1620, Cristóbal de Urgel commissioned the building of a chapel next to the main altar to serve as a burial place for himself and his family, along with the creation of the main altarpiece, sacristy, and other improvements.
In 1724, the Viceroy of New Spain, Baltasar de Zúñiga, ordered the rebuilding of the oratory due to the ruinous state of the building. This small hexagonal-domed sanctuary, roofed with slate and topped with a lantern was, however, badly damaged by a fire in 1936. The Archconfraternity of San Pedro, San Andrés, and San Isidro oversaw its rereconstruction between 1940 and 1941, faithfully following the 1724 design.
On 15 May, the feast day of the capital’s patron saint, San Isidro Labrador, the traditional open-air mass is celebrated on the esplanade near the chapel, attracting an ever-growing number of worshippers each year. The people of Madrid commemorate the occasion with a pilgrimage around the sanctuary, drinking from the miraculous spring and sharing meals in the surrounding area. During the festivities, the saint’s relic is venerated, and various religious services take place. The celebration is considered one of Madrid’s most popular and traditional festivals.