The Palace of King Martin the Humane is located within the third enclosure of the monastery, integrated between the pre-existing monastic structures. It occupies the upper floors of the cloister atrium, the old wine presses, the passageway to the priory and the galilee or vestibule of the church. From the architectural point of view, it is considered one of the jewels of Catalan civil Gothic.

Its construction was ordered by King Martin I the Humane, and work began in 1397 under the direction of the master builder Arnau Bargués, also known for being the author of the Casa del Consejo de Ciento in Barcelona. The works were left unfinished in 1406, but in 1966 the pending works were resumed and a careful restoration of the building was carried out.

Today, the palace houses the monastery's museum, allowing visitors to appreciate both its historical and artistic value.