When the first bishop took possession of his see, he started to build his cathedral. Instead of choosing Osma itself as the seat, however, he selected the site of a convent on the opposite banks of the Duero (to the north), where the Virgin had appeared to a shepherd. Houses soon grew up around the temple and, to distinguish it from Osma, the new city was called Burgo de Osma, a name it still retains. In 1232, not a hundred years after the erection of the cathedral, it was totally destroyed, excepting one or two chapels still to be seen in the cloister, by Juan Dominguez, who was bishop at the time, and who wished to possess a see more important in appearance than that left to him by his predecessor, St. Peter. The building as it stands to-day is small, but highly interesting. The original plan was that of a Romanesque basilica with a three-lobed apse, but in 1781 the ambulatory walk behind the altar joined the two lateral aisles. Two of the best pieces of sculptural work in the cathedral are the _retablo_ of the high altar, and the relief imbedded in the wall of the _trascoro_--both of them carved in wood by Juan de Juni, one of the best Castilian sculptors of the sixteenth century. The plastic beauty of the figures and their lifelike postures harmonize well with the simple Renaissance columns ornamented here and there with finely wrought flowers and garlands. The chapel where St. Peter of Osma's body lies is an original rather than a beautiful annex of the church. For, given the small dimensions of the cathedral, it was difficult to find sufficient room for the chapels, sacristy, vestuary, etc. In the case of the above chapel, therefore, it was necessary to build it above the vestuary; it is reached by a flight of stairs, beneath which two three-lobed arches lead to the sombre room below. The result is highly original. The same remarks as regard lack of space can be made when speaking about the principal entrance. Previously the portal had been situated in the western front; the erection of the tower on one side, and of a chapel on the other, had rendered this entrance insignificant and half blinded by the prominent tower. So a new one had to be erected, considered by many art critics to be a beautiful addition to the cathedral properly speaking, but which strikes the author as excessively ugly, especially the upper half, with its balcony, and a hollow arch above it, in the shadows of which the rose window loses both its artistic and its useful object. So, being round, it is placed within a semicircular sort of _avant-porche_ or recess, the strong _contours_ of which deform the immense circle of the window. To conclude: in the cathedral of Osma, bad architecture is only too evident. The tower is perhaps the most elegant part, and yet the second body, which was to give it a gradually sloping elegance, was omitted, and the third placed directly upon the first. This is no improvement.