▁park ▁is ▁in ▁the ▁Dr ift less ▁Area ▁of ▁Iowa . ▁This ▁region ▁escaped ▁being ▁gla ci ated ▁in ▁the ▁last ▁ice ▁age , ▁while ▁regions ▁to ▁the ▁east ▁and ▁west ▁were ▁not ▁sp ared . ▁The ▁park ▁has ▁been ▁subject ed ▁to ▁hundreds ▁of ▁thousands ▁of ▁years ▁of ▁natural ▁non - g la cial ▁er os ion . ▁▁ ▁The ▁park ' s ▁c aves , ▁lim estone ▁form ations ▁and ▁rug ged ▁bl uff s ▁represent ▁a ▁step ▁back ▁in ▁ge ological ▁time ▁of ▁thousands ▁of ▁years . ▁St al act ites ▁once ▁hung ▁from ▁the ▁ce il ings ▁and ▁stal ag mit es ▁rose ▁from ▁the ▁floor . ▁Sou venir ▁hun ters ▁have ▁ro bb ed ▁the ▁c aves ▁of ▁this ▁rare ▁beauty , ▁but ▁many ▁form ations ▁remain . ▁ ▁The ▁park ' s ▁lim estone ▁c aves , ▁arch es ▁and ▁chim ne ys ▁including ▁Dance hall ▁C ave , ▁Hern ado ' s ▁H ide away , ▁Shin bone ▁C ave , ▁W ye ▁C ave , ▁and ▁an ▁un mark ed ▁cave ▁within ▁the ▁Dance hall ▁Ca vern ▁locally ▁known ▁as ▁Ste el gate ▁C ave . ▁ ▁Today ▁a ▁modern ▁interpret ive ▁center ▁outside ▁the ▁park ▁entrance ▁provides ▁maps ▁and ▁other ▁inform ational ▁materials . ▁Inside ▁the ▁park , ▁a ▁central ▁map ▁k ios k ▁includes ▁charts ▁of ▁some ▁of ▁the ▁more ▁interesting ▁c aves . ▁ ▁History ▁ ▁Art ifact s ▁such ▁as ▁pot tery , ▁as ▁well ▁as ▁tools ▁and ▁project ile ▁points