Many Spanish churches and chapels are dedicated to the Virgin Mary. This hermitage in Tembleque has the additional name "Purísima Concepción", i.e. it is dedicated to the "Immaculate Conception" as a special Marian feast.
This term, which today may sound a bit theoretical and difficult to understand, is intended to say that the Virgin Mary was freed from the burden of original sin - which otherwise every human being carries within themselves - from the very beginning through the grace of God. This meant that when the archangel later announced to her in Nazareth that she would give birth to the Son of God, she was willing to answer YES of her own free will.
In 1854, Pope Pius IX elevated this article of faith to dogma. The feast for this occasion - and at the same time the patron saint of this place of worship - which in the Catholic liturgy is called the "Solemnity of the Immaculate Conception of the Virgin Mary" is celebrated annually on December 8th.