▁the ▁Ang lo ▁Sax on ▁den , ▁a ▁hole ▁or ▁valley . ▁The ▁lack ▁of ▁evidence ▁found ▁in ▁them ▁has ▁led ▁to ▁long ▁arguments ▁as ▁to ▁their ▁function . ▁ ▁Form ▁ ▁The ▁general ▁outline ▁of ▁the ▁formation ▁of ▁these ▁c aves ▁is ▁invari ably ▁the ▁same . ▁The ▁entrance ▁is ▁a ▁vertical ▁sh aft ▁some ▁ 3 ▁feet ▁( 1 ▁m ) ▁in ▁diameter ▁falling , ▁on ▁an ▁average , ▁to ▁a ▁depth ▁of ▁ 6 0 ▁feet ▁( 2 0 ▁m ). ▁The ▁depth ▁is ▁reg ulated ▁by ▁the ▁depth ▁of ▁the ▁ch alk ▁layer ▁from ▁the ▁surface , ▁although ▁ch alk ▁can ▁be ▁found ▁within ▁a ▁few ▁feet , ▁or ▁even ▁inches , ▁from ▁the ▁surface . ▁A ▁depth ▁of ▁from ▁ 4 5 ▁to ▁ 8 0 ▁feet ▁or ▁more , ▁is ▁a ▁characteristic ▁feature . ▁ ▁F ooth olds ▁were ▁cut ▁into ▁the ▁sides ▁of ▁the ▁sh aft ▁to ▁allow ▁the ▁min ers ▁to ▁clim b ▁in ▁and ▁out . ▁The ▁sh aft , ▁when ▁the ▁ch alk ▁is ▁reached , ▁wid ens ▁out ▁into ▁a ▁dom ed ▁chamber ▁with ▁a ▁roof ▁of ▁ch alk ▁some ▁ 3 ▁feet ▁thick . ▁The ▁walls ▁frequently ▁contract ▁somewhat ▁as ▁they ▁near ▁the ▁floor . ▁As ▁a ▁rule ▁the ▁main ▁chamber ▁is ▁ 1 6 ▁to ▁ 1 8 ▁feet ▁in ▁height , ▁beneath ▁each ▁sh aft . ▁From ▁this ▁excess ive ▁height ▁it ▁has ▁been ▁infer red ▁that ▁the ▁c aves ▁were ▁not ▁primarily ▁intended ▁for ▁habit ations ▁or ▁even