It is 17.5 m (57 ft 5 in) in length, 5.2 m (17 ft) thick, 1.5 m (1 ft 8 in) in height, raised on a low plinth, and battering to the top. The summit is crowned by crenellated battlements on three sides only, the inner side facing the gate being left open and free. Access to the top could be gained by means of ladders, no other means of going up having been provided. It served as an advanced defence work protecting both the gate and the bridge a few feet away. By the side of this screen is a huge teak pillar resting on a brick plinth stepped off on two sides, and carrying near the top a wooden board on which is carved an inscription giving the name of the gate, and the year and date on which it was built. Each of the four walls has 13 bastions for a total of 48 bastions. (Bastions at each corner are merged into one, hence 48 in total.) All the intermediate bastions are surmounted by a quintuple-roof pavilion. The barge-board of these many-gabled roofs are covered with carvings. The moat Surrounding the walls, at a distance of about 18 m (60 ft) from them, is a moat 64 m (210 ft) wide, and of an average depth of 4.5 m (15 ft). In the case of foes armed with ancient weapons, this moat would no doubt have presented a rather formidable obstacle to the besieging army, whose crafts would have been completely exposed to the missiles of the warriors protected by the merlons on the ramparts and on the barbicans. The moat was originally spanned over by five wooden bridges, four of which lead to the four principal or middle gates, that is one to each face of the walls. The fifth leads up to the south-western gate, used during the times of monarchy for amingala or inauspicious occasions such as to carry off dead bodies. The British constructed two additional bridges one at the south-west and the other at the north-west corner, to allow of materials and supplies for the troops into the fort. The five original bridges are similar in design and are in unison with the defensive character of the fort and the moat. Two earthen embankments encased within brick walls form the abutments running into the moat from both banks. The space between is