It consists of two levels and a pinnacle 

On it, you can see statues of the patron saints Cosmas and Damian, while in the center, there is a delicate relief of the Virgin of La Merced with the founders of the order. 

The interior was originally a single-nave structure with a transept, but it was later modified to include three naves by connecting with the side chapels. 

On the sides of the altar, there are two enormous canvases depicting the genealogy of the Mercedarian saints.