▁southern ▁section ▁of ▁the ▁walk ▁was ▁demol ished ▁to ▁accommod ate ▁the ▁yard ▁for ▁the ▁new ▁ga ol . ▁ ▁In ▁ 1 8 4 6 , ▁the ▁n ort he astern ▁corner ▁of ▁the ▁walls ▁was ▁bre ached ▁by ▁the ▁Ch ester ▁and ▁Holy head ▁Railway . ▁ ▁New gate ▁was ▁opened ▁in ▁ 1 9 3 8 ▁to ▁bridge ▁a ▁new ▁road ▁built ▁to ▁rel ieve ▁traffic ▁con g estion ▁in ▁the ▁city ▁centre , ▁and ▁in ▁ 1 9 6 6 ▁St ▁Martin ' s ▁Gate ▁was ▁built ▁across ▁the ▁Inner ▁Ring ▁Road . ▁ ▁The ▁" w alls , ▁tower , ▁gates ▁and ▁post ern s ▁of ▁the ▁City ▁of ▁Ch ester " ▁are ▁recogn ised ▁as ▁a ▁scheduled ▁monument . ▁ ▁All ▁the ▁to wers ▁associated ▁with ▁the ▁walls ▁have ▁been ▁designated ▁as ▁Gra de   I ▁listed ▁buildings , ▁as ▁have ▁all ▁the ▁sections ▁of ▁the ▁wall , ▁other ▁than ▁that ▁between ▁Br id geg ate ▁and ▁the ▁former ▁County ▁Hall ▁( now ▁used ▁by ▁the ▁University ▁of ▁Ch ester , ▁which ▁is ▁listed ▁Gra de   II *. ▁ ▁The ▁gates ▁are ▁all ▁designated ▁Gra de   I ▁except ▁for ▁Old ▁New gate , ▁which ▁is ▁Gra de   II *, ▁New gate , ▁which ▁is ▁Gra de   II , ▁and ▁St ▁Martin ' s ▁Gate , ▁which ▁is ▁not ▁listed . ▁ ▁The ▁three ▁gr ades ▁of ▁listing ▁are ▁defined ▁as ▁follows . ▁ ▁Gra de   I ▁buildings ▁are ▁" of ▁exception al