The line of the Roman walls ran from the Tower straight to Aldgate; there making an angle, it continued to Bishopsgate. From there it turned eastward to St. Giles's Churchyard, where it veered south to Falcon Square. At this point it continued west to Aldersgate, running under Christ's Hospital, and onward to Giltspur Street. There forming an angle, it proceeded directly to Ludgate towards the Thames, passing to the south of St. Andrew's Church. The wall then crossed Addle Street, and took a course along Upper and Lower Thames Street towards the Tower. In Thames Street the wall has been found built on oaken piles; on these was laid a stratum of chalk and stones, and over this a course of large, hewn sandstones, cemented with quicklime, sand, and pounded tile. The body of the wall was constructed of ragstone, flint, and lime, bonded at intervals with courses of plain and curve-edged tiles. That Roman London grew slowly there is abundant proof. In building the new Exchange, the workmen came on a gravel-pit full of oyster-shells, cattle bones, old sandals, and shattered pottery. No coin found there being later than Severus indicates that this ground was bare waste outside the original city until at least the latter part of the third century. How far Roman London eventually spread its advancing waves of houses may be seen from the fact that Roman wall-paintings, indicating villas of men of wealth and position, have been found on both sides of High Street, Southwark, almost up to St. George's Church; while one of the outlying Roman cemeteries bordered the Kent Road. From the horns of cattle having been dug up in St. Paul's Churchyard, the monks, ever eager to discover traces of that Paganism with which they amalgamated Christianity, conjectured that a temple of Diana once stood on the site of St. Paul's. A stone altar, with a rude figure of the amazon goddess sculptured upon it, was indeed discovered in making the foundations for Goldsmiths' Hall, Cheapside; but this was a mere votive or private altar, and proves nothing; and the ox bones, if any, found at St. Paul's, were merely refuse thrown into a rubbish-heap outside the old walls. As to the Temple of Apollo, supposed to have been replaced by Westminster Abbey, that is merely an invention of rival monks to glorify Thorney Island, and to render its antiquity equal to the fabulous claims of St. Paul's. Nor is there any positive proof that shrines to British gods ever stood on either place, though that they may have done so is not at all improbable.