The church was built in the form of a cross, which was contrary to the form in common use prior to the twelfth century, and it is hence inferred that Madog availed himself of the aid of the Free Masons, as they were incorporated about this time, and were the chief undertakers of such works. Sir Christopher Wren, in his Parentalia, describes their government as regular, and they were wont to make an encampment in huts. A surveyor governed in chief; every tenth man being called a warden and overlooking nine. They ranged from country to country as they found churches to be built, and are supposed to have first introduced the cruciform style for religious edifices. The eastern end of the church appears the most ancient, and the three lancet-like windows have a very peculiar effect. The northern side has been almost destroyed, and there is no vestige of the roof except in the eastern side of the southern transept. The choir was without aisles, but each transept had one on the east side, which seem to have been used as chapels. The west front of the church affords some admirable specimens of ancient Gothic architecture. The chief entrance was through the ornamental pointed-arch gateway at the west end, over which is a fine window, consisting of three lancet-shaped arches, surmounted by a circular or rose window of eight divisions. Above this window are the remains of a mutilated inscription, of which the following is probably a correct translation:— “The Abbot Adam did this work. May he rest in happy peace. Amen.” High up in the southern wall is to be seen a small loop-hole, communicating with a passage which leads over the vaulting of the southern transept aisle to the abbatial building adjoining the church. This passage is now blocked up, but it is conjectured to have served either as a closet wherein the Abbot could attend service privately, or else as a place of confinement or penitence for the monks. The architecture of this portion of the church corresponds in its style with the date of its erection, the commencement of the thirteenth century; the lancets, with their mouldings, are strictly of that date, and the capitals of the shafts, which are worked with great boldness, are of the late Norman period, rather than of that which is called early-pointed. The side windows are each of two lights, the principal arch-head being solid, but pierced with a single aperture divided into six foliations. Above these three windows run a kind of framework, similar in some respects to that at the eastern end of the choir. On the external face of the western end are two bold buttresses of a single stage, that on the south-eastern side being pierced for loop-holes for a circular staircase formed in the thickness of the walls and itself.