was unable to see its completion. The construction resumed under architect Juan Sequero de Matilla in 1616 and the tower was finished in 1617. The new tower had imperfections, however, and required repairs only a few decades later in the mid-17th century. The cathedral hired architect Gaspar de la Peña to fix the problems. He reinforced the tower and modified the initial design of the Puerta del Perdón ("Door of Forgiveness") which passed through the tower's base. In 1664 Gaspar added a new cupola to the top of the belfry onto which he raised a statue of Saint Raphael made by the sculptors Pedro de la Paz and Bernabé Gómez del Río. In 1727 the tower was damaged by another storm and in 1755 pieces of it (mainly decorative details) were damaged by the 1755 Lisbon Earthquake. A French architect, Baltasar Dreveton, was charged with restoring and repairing the structure over a period of 8 years. In the new Capilla Mayor, after its completion by Juan de Ochoa, Bishop Diego de Mardones initiated the construction of its main altarpiece and provided a significant donation himself for the project. The altarpiece was designed in a Mannerist style by Alonso Matías and construction began in 1618. Other artists who were involved in its execution included Sebastián Vidal, Pedro Freile de Guevara, and Antonio Palomino. In March 1748 construction on the choir stalls began, with the commission awarded to Pedro Duque Cornejo. It was initially funded with the help of a large bequest by Archdeacon José Díaz de Recalde in 1742. Work on the choir stalls finished in 1757, though Duque Cornejo – who had worked on it continuously for nearly a decade – died just two weeks before the finished choir was officially opened. Modern restorations (19th–21st centuries) In 1816 the original mihrab of the mosque was uncovered from behind the former altar of the old Chapel of San Pedro. Patricio Furriel was responsible for restoring the mihrab's Islamic mosaics, including the portions which had been lost. Further restoration works concentrating on the former mosque structure were carried out between 1879 and 1923 under the direction of Velázquez Bosco, who among other things dismantled the baroque elements that had been added to the Villaviciosa Chapel and uncovered the earlier structures there. During this period, in 1882, the cathedral and mosque structure was declared a National Monument. Further research work and archaeological excavations