The construction of the Basilica of the Sacramentinos, an unquestionable landmark of the area, began in 1912. The project was in charge of the Chilean architect Ricardo Larraín Bravo and included the participation of the French engineer Victor Auclair, who brought to Chile the reinforced concrete construction system.

Of a Byzantine Romanesque style, it is said to have been the second temple in Chile built in reinforced concrete. This large temple stands out for its similarity with the church Sacré Coeur of Paris but, in spite of which many set out, it is not a replica of said temple.

The first part that was built was the Crypt that was completed seven years after laying the first stone, which gives rise to an underground church composed of three naves, low vaulted ceilings and arcade with wide Corinthian columns. It has several windows located in the lateral chapels that accommodate the confessionals; however, they are not enough to provide the space with great lighting. The moisture problems that the temple has in general, here are very obvious.

The Crypt was inaugurated on June 15, 1919 and only people that were invited were able to enter.

In 1920, the construction of the Upper Temple continues, which erects in a very large volume over a Latin cross floor plan. It consists of three naves separated by arcade with wide Corinthian style columns and vaulted ceilings. The area of the transept has huge columns of the same style.

The walls are plastered with details of medallions and flowers.

The gallery is also composed of arcade with Corinthian columns and equipped with large windows that provide great luminosity. Towards the choir a large rose window illuminates that space. Towards the transept large windows are raised with beautiful vitreaux.

The triforium made up by three large windows in each segment, two small windows and a higher central one, all of them with a semicircular arch and Corinthian style columns. This whole section together with the gallery are the main source of natural light.

At the center there is a large dome. The first one that was built was demolished on January 23, 1929 for the purposes of building a lighter one and being able to illuminate it. The works were finished in May of the same year. It has a lantern with stained glass windows.

The parquet floor of the upper temple, which is one of the first manufactured in Chile, is noteworthy.

Since many works remained unfinished, such as the total completion of the external coatings and stucco, the reinforced concrete was exposed and for years it has been exposed to rainfall moisture, which has brought about a permanent deterioration in the construction. In addition to the damages caused by the earthquakes and the high maintenance costs, several areas of this temple are exposed to material wear.

The façade is guarded by Worshiper Angels, sculptures commissioned to sculptor Alirio Pereira and made in white cement, as well as the images of the Sacred Heart of Jesus and Saint Peter Julian Eymard, both facing the Almagro square and made by the same sculptor.

The Upper Temple was handed over for its partial use on March 22, 1931.

It was declared a National Monument in 1991.