The cathedral ground plan is in the shape of a Latin cross. The interior is formed by a nave and two aisles, another nave with a broad transept and a high chapel surrounded by an ambulatory. The head and transept were built in the 12th century, the lower nave and aisles and the vaults of the transept in the 13th, the upper nave in the 14th. The ribbed vaults of the nave and the upper section of the high chapel were rebuilt in the 15th century. This is, all in all, affine example of Cistercian or early Gothic architecture. The basic style dates to the period of transition from Romanesque to Gothic with influences from the art of Aquitania and Burgundy, but there can be no doubt that this is one of the finest Cistercian cathedrals. The bare vaults are magnificent; the high windows of the aisles retain their pure Romanesque style, whilst those of the nave are Gothic.
Three of the columns in the choir have plain shaft, and were the first to be installed in the 12th century. The rest are made up of clustered piers. The right-hand column in the crossing is also differentiated from the rest, though it is in the same style.
The many side chapels, the altars, the choir, the presbytery, etc., all feature splendid works of Spanish art, all of which are described and analyzed separately. The left-hand side of the transept, where stands the Altar of Santa Librada, is adorned by a lovely rose window of daring execution.
As regards the ribs and ogives of the vaults covering the cathedral, partly built in the 13th century, there are ogive arches whose section is formed by con cave and convex curves, taken from the gothic art of northern France.
A certain debate has arisen as to whether it is the ribs or the web which forms the Gothic vault. Some scholars are of the theory that the web forms the true Vault, the balance in itself. There are examples of such vaults in Sigüenza Cathedral which have lost their ribs but which continue to hold overall.
Nave and Aisles
The rigorously austere interior is made up of a nave and two aisles separated by strong pillars. These, exceptionally are square, with twin columns embedded in the four fronts, covering them almost completely. The aisles, not as high as the nave, were built in the 13th century, whilst the nave began to be built in 1495 and are in late-Gothic style, though the ribbed vaults of the nave and the higher section of the high chapel have since been rebuilt.
The nave terminates in the transept, closed off by the grille of the choir. Opposite, another beautiful grille closes the high chapel, which is polygonal in ground plan. The roof and lantern in the transept, damaged by bombs in 1936, have been rebuilt, with high Gothic vaults supported by thick clustered and cylindrical pillars.
The nave windows are larger than normal for other similar churches, but this higher section of the cathedral was built during the first quarter of the 13th century, under the influence of the gothic art of northern France.
The various sections of the nave are larger than they are wide. In consequence, the supports are rather separate one from another, in contrast to the norm for wholly Gothic churches. For this reason, as the nave is quite wide, the vault covers a: considerable surface – 103 meters – producing great thrust.
Two measurements are sufficient to give an idea of the large dimensions of Sigüenza cathedral: the 1 0.2 meters width of the nave and the 27 meters height of the keystones of this same nave.
As we have mentioned, the church ground plan takes the form of a large Latin cross. From the foot of the church in the west front to the Altar of Nuestra Señora del Rosario in the center of the ambulatory, the length of the cathedral is 86 meters, whilst its width in the transept or crossing is 38 meters.
There are many burial stones in the floor of the nave and aisles, most of them much worn now. Their faded inscriptions recall the names and deeds of bishops, canons and noblemen of the city. The stones are engraved with coats of arms and mottoes. Life passes over them at every instant, little by little extinguishing the eagles, helmets and castles of the escutcheons. Few of the inscriptions on the marble tombs are legible still. The constant rubbing of feet has gradually erased the letters, for the natural law of life, death and oblivion decree that of what was once nothing shall remain, not even its memory.
Almost all the double-columned pillars rest on high, sturdy sacies, molded and octagonal in shape.
The profiles of its bases are formed by an upper bead flush and a molding below, between which is a casement molding of little depth. There are always claws – and almost always leaves – at the angles of the plinth. Frequently the lower quarter of the bead flush is decorated by semicircular moldings forming a festoon.
The quality of the stone used determines how fine the molding can be, and it is possible to achieve good profiles using sandstone from Sigüenza.
All, or almost all, the pillars at the foot of Sigüenza Cathedral, in correspondence with all the pilasters, have double columns on all four or two of their fronts, flanked by others supporting the doubled arches and with one at each angle from where the ogives spring, embedded into the pillar from between one-half and one-third, approximately, of their diameter.
The outstanding characteristic of this type of pillar is its large section and the consequent extraordinary robustness, achieving maximum complexity and magnitude through being enclosed by 20 columns.
The largest pillars in Sigüenza Cathedral have a maximum width of 3.76 meters. This size is generally from one-third to one-quarter of the width of the nave, and in Sigüenza Cathedral it is just over one-third.
The diameter of the columns from which the ogive arches spring is greater than that of those supporting the exterior thread of the footing and supporting arches.
The pillars with double column show clear influences from the architecture of Languedoc.
The head of the transept nave was built in the 12th century, the vaults in the 13th.
On the left-hand side of the transept is a lovely rose window of the most daring tracery.
The arms of the crossing are covered by sexpartite vaults which conform to the Anglo-Norman model.
The crossing is from where the splendid proportions of the cathedral can best be appreciated. The main arch of the presbytery is of the most sovereign majesty, made up as it is of groups of columns with fine capitals. These pillars were restored in magnificent fashion worthy of the highest praise, with the suppression of the spaces made in them to give access to the pulpits. These hollows were made at a date subsequent to their original construction, greatly endangering their stability and against all rules. Adjoining the four pillars in the center of the crossing, at the upper section and before coming to the first order of capitals, we find four statues dating to the second third of the 14th century.
These represent the August Mystery of the Incarnation of the Lord prophesied by Isaiah and Zacharias on the left, and the Annunciation of the Archangel Gabriel to Our Lady the Virgin Mary on the right, with the coat of arms of Bishop Simón Girón de Cisneros (1300-1326).