, ▁it ▁was ▁inhab ited ▁by ▁about ▁ 2 0 0   people ▁living ▁in ▁ 1 4   round h ouses , ▁and ▁was ▁built ▁on ▁a ▁mor ass ▁on ▁an ▁artificial ▁foundation ▁of ▁tim ber ▁filled ▁with ▁br ush wood , ▁bra cken , ▁rub ble ▁and ▁cl ay . ▁ ▁The ▁valley ▁was ▁used ▁during ▁Rom ano - B rit ish ▁period ▁when ▁it ▁was ▁the ▁site ▁of ▁salt ▁extra ction . ▁At ▁that ▁time , ▁the ▁Br ue ▁formed ▁a ▁lake ▁just ▁south ▁of ▁the ▁h illy ▁ground ▁on ▁which ▁G last on bury ▁stands . ▁According ▁to ▁legend ▁this ▁lake ▁is ▁one ▁of ▁the ▁locations ▁suggested ▁by ▁Arthur ian ▁legend ▁as ▁the ▁home ▁of ▁the ▁Lady ▁of ▁the ▁Lake . ▁Pom par les ▁Bridge ▁stood ▁at ▁the ▁western ▁end ▁of ▁this ▁lake , ▁guard ing ▁G last on bury ▁from ▁the ▁south , ▁and ▁it ▁is ▁suggested ▁that ▁it ▁was ▁here ▁that ▁Sir ▁Bed iver e ▁threw ▁Ex cal ib ur ▁into ▁the ▁waters ▁after ▁King ▁Arthur ▁fell ▁at ▁the ▁Battle ▁of ▁Cam l ann . ▁John ▁L eland ▁noted ▁in ▁the ▁ 1 6 th ▁century ▁that ▁the ▁bridge ▁had ▁four ▁arch es , ▁while ▁W . ▁Ph el ps ▁in ▁an ▁ 1 8 3 9 ▁illustr ation ▁as ▁having ▁only ▁two ▁arch es , ▁one ▁pointed , ▁probably ▁from ▁the ▁ 1 4 th ▁or ▁ 1 5 th ▁century , ▁and ▁the ▁other ▁round . ▁Ex c av ations ▁in ▁ 1 9 1