A peculiarity of this church of St. Francisco, as of the cathedral of Evora, which I shall mention presently, is that the brown granite blocks of which it is constructed are clearly marked out with staring white divisions of cement, either real or simulated. The effect is one of very questionable taste, but the peculiarity is not a modern innovation, and the series of white transverse lines traced upon the brown background has some attraction from its very strangeness. The story goes that this monastery-church, founded originally in 1224, twice fell down, and when, after the second disaster late in the fifteenth century, the famous architect, Martin Lourenço, was commissioned to construct a new church, he swore that his building, at least, should never share the fate of its predecessors. Instead of a single main outer wall he built two on each side of the church, all of similar height, the space between the inner and outer walls being about five feet or less, and in the lower portion of this space the side chapels are accommodated. The two walls were tied together by transverse walls of similar strength and height between the chapels, and upon each of these transverse walls, which are carried over the roof to the opposite pair of walls, similarly constructed, the roof arches rest. The roof is, therefore, divided into six independent sections, each one supported by its own separate walls and arch. As if this were not enough, a similar arrangement was made below the ground, where corresponding sets of transverse walls were carried across to the other side, and thus the whole nave consisted of six complete and self-supporting bodies joined together. Even this did not satisfy Martin Lourenço. He built yet another wall longitudinally along the central ridge of the roof, and a similar one underground along the same axis binding together both above and below the transverse sections from end to end, and increasing the stability of the building by the added weight. All this it is, of course, impossible to see from the inside, but from the praça the top battlements of the four long lines of wall and the roof-ridge are discernible, and the skeleton of the church, so to speak, can be understood. A door in the transept leads to an extraordinary chapel of considerable size (58 feet long by 34 broad), divided into a nave and two aisles, the whole of the walls, pillars, and ceiling of which are lined or constructed of skulls and other human bones, arranged in symmetrical patterns. The remains of many thousands of human beings are contained in this ghastly chamber, probably constructed by the monks in the seventeenth century from the contents of ancient crypts and charnel-houses. The specially venerated figure of our Lord, of which this was formerly the chapel, has now been transferred to an adjoining apartment better adapted for modern worship.