The greatest peculiarities of this building exist in the wall at the western end. I will say nothing about the windows and pilasters, of which we have no other Greek examples, nor of a recess in the upper part at the south-west angle, taken out of the thickness of the walls, which is quite unaccountable, but direct your attention to the basement. In this we find a doorway under one of the internal pilasters, and consequently also under one of the external semicolumns. M. Fauvel contends, that this opening is not coeval with the building, but has been broken through for some purpose of later convenience; and Stuart, by altogether omitting it, seems to have been of the same opinion. It is however of the original construction, for the face of the work within the opening corresponds with that of the face of the building, without any marks of the stones having been cut, or in any way altered, and there are no marks of cramps, which since the walls are cramped, as above-mentioned, in both directions, must inevitably have been visible had there originally been no opening. These seem to me pretty strong proofs, but there is another perhaps still more convincing. I have already mentioned the method adopted in these edifices to obtain strength over the openings, by setting the blocks on edge, and making the course double the height of the adjoining courses; this is the case here; a large block, equal to two courses, occurs above the opening. A door in such a situation appears remarkable, but an opening under the angle of the building at the very point of its junction with the Pandroseum, is still more extraordinary: this requires greater strength, and accordingly is covered by a great stone occupying three courses; 14 feet 6 inches and three quarters long, 4 feet 9 inches and three quarters high, and 2 feet 2 inches and three quarters thick. The top of the door marked by Stuart, as giving an entrance to the Pandroseum, is immediately under the surbase moulding of the gallery, 2 feet 3 inches and a quarter above the pavement of the portico of the Erectheum; that of the door under the gallery is two courses lower, or 3 feet 2 inches and a half, while the door under the angle is yet one course lower: all this contrivance may perhaps have had some reference to the access to the spring of salt water; but without considerable excavations the problem cannot be solved.