Task: Question Answering
Input (English): Passage: In the 15th century the dome was added and the naves extended back of the choir, uniting the building to the tower and forming a main entrance. Archbishop Luis Alfonso de los Cameros began the building of the main chapel in 1674; the walls were decorated with marbles and bronzes in the Baroque style of that period. At the beginning of the 18th century the German Conrad Rudolphus built the façade of the main entrance. The other two doors lead into the transept; one, that of the Apostles in pure pointed Gothic, dates from the 14th century, the other is that of the Paláu. The additions made to the back of the cathedral detract from its height. The 18th-century restoration rounded the pointed arches, covered the Gothic columns with Corinthian pillars, and redecorated the walls. The dome has no lantern, its plain ceiling being pierced by two large side windows. There are four chapels on either side, besides that at the end and those that open into the choir, the transept, and the sanctuary. It contains many paintings by eminent artists. A silver reredos, which was behind the altar, was carried away in the war of 1808, and converted into coin to meet the expenses of the campaign. There are two paintings by Francisco Goya in the San Francesco chapel. Behind the Chapel of the Blessed Sacrament is a small Renaissance chapel built by Calixtus III. Beside the cathedral is the chapel dedicated to the Our Lady of the Forsaken (Virgen de los desamparados or Mare de Déu dels Desamparats). Question: When was the dome built?
Output (English): 15th century