 Bath and North East Somerset has <unk> Grade I listed buildings , one of the highest concentrations in the country , covered by about 100 English Heritage listings . The oldest sites within Bath are the Roman <unk> , for which the foundation piles and an irregular stone chamber lined with lead were built during the Roman occupation of Britain , although the current building is from the 18th century . Bath Abbey was a Norman church built on earlier foundations , although the present building dates from the early 16th century and shows a late <unk> style with flying buttresses and <unk> pinnacles <unk> a <unk> and pierced parapet . The medieval era is represented by the remains of the city walls in Upper Borough <unk> . 
