The Chapel of the Founders, in Manueline style, was built in the first quarter of the 16th century at the initiative of Abbess D. Isabel de Castro, to house the tombs of the founders of the Convent, Dona Teresa Martins and D. Afonso Sanches.

The tombs were carved in stone by Diogo Pires, son, from Coimbra, considered the best Portuguese sculptor of the Manueline era.

The prince poet, in knight's costume, holding his warrior sword in one hand and a spear in the other. At his feet a lion, symbol of his noble lineage. D. Afonso's coat of arms appears represented on the face of his feet.

D.Teresa wears the habit of Sister Terceira de S. Francisco, with a veil and towel concealing her head, and a cord encircles her waist. In his hands he holds a book, alluding to his works of devotion. At his feet a deer symbolizes the Christian who redeems himself from sins by Penance.

On the longitudinal faces of the tomb, magnificent round-shaped reliefs recall the coming of Jesus to the world: Birth, Adoration of the Magi, Circumcision, Visitation, Annunciation, flight to Egypt; at the top of the head, Santa Clara was expelled from her Monastery of Assisi by the Saracen invaders.

Two smaller tomb boxes, hold the remains of two children who died in childhood. In one of them the representation of the evangelists, S.Marcos, S.Lucas and S.João; in the other figures of church priests: S.Gregorio Magno, S.Jeronimo, Sto. Augustine and Sto. Ambrosio.