The plan is admirable,--at once dignified and harmonious, and the semicircular Romanesque termination is striking. The total length is some 340 feet, its entire width, some 156; the nave is 43 and the side aisles are 32 feet wide. It is thus logical, symmetrical, and fully developed in all its members. Beyond the side aisles stretches a row of chapels separated from each other by transverse walls. As the transepts, which are of the same width as the nave, do not project beyond the chapels of its outer aisles, the Latin cross disappears in plan. The nave, aisles and chapels consist of five bays up to the crossing crowned by the great dome. Beyond this comes the vault of the Capilla Mayor and the semicircular apse surrounded by a seven-bayed ambulatory, or "girola," and an equal number of radiating pentagonal chapels. The chevet is clear in arrangement and noble in expression. Entrances lead logically into the nave and side aisles of the western front and into the centres of the northern and southern transepts, while cloisters which abut to the south are entered through the fifth chapel. When Segovia was built, Spaniards were thoroughly reconciled to the idea of placing the choir west of the crossing and the Capilla Mayor east, and consequently the latter was designed no larger than was requisite for its offices, and a space was frankly screened off between it and the choir for the use of the officiating clergy. The third and fourth bays of the nave contained the choir.
As one enters the church, there is a consciousness of joy and order. The stone surfaces are just sufficiently warmed and mellowed by the glorious light from above. The piers are very massive and semicircular in plan; the foliage at their heads underneath the vaulting is so delicate and unpronounced that it scarcely counts as capitals. The walls of the chapels in the outer aisles, as well as round the ambulatory, are penetrated by narrow, round-headed windows, as timid and attenuated as those of an early Romanesque edifice; the walls of the inner aisle, by triple, lancet windows; and the clerestory of the nave, by triple, round-headed ones. Under them, in the apse, is a second row of round-headed blind windows. None of them have any tracery whatever. The glass is of great brilliancy of coloring and exceptional beauty, but the designs are as poor as the glazing is glorious. In the smaller windows, the subjects represent events in the Old Testament; in the larger, scenes from the New. Around the apse much of the old, stained glass has been shamefully replaced by white, so as to admit more light into this portion of the building.