▁small , ▁w alled ▁town . ▁This ▁town ▁had ▁a ▁rectangle ▁of ▁wooden ▁walls , ▁protected ▁by ▁a ▁" V " ▁sh aped ▁d itch , ▁stopping ▁just ▁short ▁of ▁the ▁modern ▁Cross ▁Street . ▁In ▁the ▁ 1 2 th ▁century ▁this ▁d itch ▁was ▁filled ▁in , ▁possibly ▁because ▁of ▁a ▁pressure ▁on ▁land ▁in ▁the ▁town , ▁and ▁the ▁town ▁of ▁A berg aven ny ▁then ▁appears ▁to ▁have ▁lack ed ▁any ▁def ences ▁until ▁the ▁late ▁ 1 3 th ▁century . ▁ ▁In ▁the ▁late ▁ 1 3 th ▁century ▁a ▁larger ▁town ▁wall ▁was ▁built ▁around ▁A berg aven ny ▁in ▁stone , ▁forming ▁an ▁o val ▁shape , ▁approximately ▁ 3 5 0 ▁m ▁by ▁ 2 1 5 ▁m ▁across . ▁The ▁wall ▁was ▁paid ▁for ▁and ▁maintained ▁by ▁mur age , ▁by ▁which ▁the ▁king ▁allowed ▁a ▁city ▁to ▁raise ▁tax es ▁on ▁the ▁imports ▁of ▁particular ▁goods . ▁ ▁By ▁the ▁ 2 1 st ▁century , ▁only ▁occas ional ▁m ason ry ▁remains ▁of ▁the ▁medieval ▁walls , ▁although ▁the ▁line ▁of ▁the ▁wall ▁can ▁be ▁seen ▁in ▁the ▁form ▁of ▁later ▁buildings ▁and ▁walls . ▁ ▁See ▁also ▁ ▁List ▁of ▁town ▁walls ▁in ▁England ▁and ▁Wales ▁Ch ester ▁city ▁walls ▁York ▁city ▁walls ▁ ▁References ▁ ▁Bibli ography ▁Clar ke , ▁Stephen ▁and ▁Jane ▁B ray . ▁( 2 0 0 3 ) ▁" The ▁Norman ▁town ▁def ences ▁of ▁A berg aven ny ," ▁Med ieval ▁Arch ae ology