The exact position of the wall of white stone, built in the reign of Dmitri Donskoi (1367), is unknown; in all probability it was within the space at present enclosed. The wall of burnt tiles, erected during the reign of Ivan III., was the work of Aleviso Fioraventi, an Italian architect; but a few years later, between 1485 and 1492, the present wall was raised on the foundations of the old one, in part by Italian workmen, in part by native artisans. This wall, repaired from time to time, has escaped all the fires and disasters which wrought such havoc elsewhere in the Kremlin; but in its original state consisted of three distinct parapets, set back and rising above each other over the ditch, much as the tiers of the old towers still remaining. The wall, the inmost of the three, is of an exaggerated Italian style, the battlements unnecessarily deep. The towers and gates are various: some as the Spasski and Troitski, Gothic; some as the Borovitski and the Gun Towers, Russian; others bastard and nondescript. The Borovitski, Tainitski, and the similar smaller square pyramidal towers, are clearly copies of the older wooden erections on the earlier walls. The design is that of carpenters, not of masons. The green tiles are the original covering; the secret of making them has been lost. For centuries the wall was painted white, the present brick colour is an innovation. [Illustration: KREMLIN--RAMPART AND GUN TOWER] An early writer states that "the wall is two miles about, and it hath sixteen gates and as many bulwarks." It is better to be precise. The length of the wall is 1 mile 700 yards, and it follows exactly the contour and windings of the hill, forming an irregular triangle; the thickness varies from 14 to 20 feet, the height from 30 to 70 feet. Throughout the entire length there is a rampart 9 feet wide and a low parapet on the inner side. This walk is paved with stone flags, and is reached from any of the towers and by special stairways within the wall. The Borovitski Gate, surmounted by a tower 200 feet high (see page 299), preserves the name of the forest (Bor), with which the hill was long ago covered, its official name is the Prechistenka Gate; here all that remains of the old church of the Nativity of St John the Baptist is conserved in the chapel on the right of the gate in entering. In the second storey is the Royal Chapel of St John, one of the ten churches of the palace; in it a service is held once a year, to which worshippers are summoned by ringing the bells on the third storey of the tower. By this gate the Tsars left the Kremlin on other than state occasions, by it Napoleon's troops entered.