 There are 90 Grade I listed buildings in the Mendip district . There are churches in the various towns and villages , however the greatest concentrations of Grade I listed buildings are in Wells and Glastonbury . In Wells these are clustered around the 10th @-@ century Cathedral Church of St Andrew , better known as Wells Cathedral , and the 13th @-@ century Bishop 's Palace . Glastonbury is the site of the Abbey , where construction started in the 7th century , and its associated buildings . The ruined St Michael 's church , damaged in an earthquake of 1275 , stands on Glastonbury Tor , where the site shows evidence of occupation from Neolithic times and the Dark Ages . The <unk> Well has been in use since Pre @-@ Christian times . Glastonbury Abbey had a wider influence outside the town : <unk> <unk> were built at <unk> and West Bradley to hold <unk> , and a Fish House was built at <unk> along with a summer residence for the Abbot ( now Manor Farmhouse ) . 
