0 0 ▁CE . ▁However , ▁recent ▁radio - car bon ▁dates ▁it ▁around ▁ 1 0 0 0 ▁B CE . ▁Early ▁Spanish ▁expl or ers ▁and ▁subsequent ▁mar in ers ▁used ▁the ▁large ▁m ound ▁as ▁a ▁land mark . ▁Today , ▁the ▁site ▁is ▁owned ▁and ▁managed ▁by ▁the ▁National ▁Park ▁Service ▁as ▁part ▁of ▁C ana ver al ▁National ▁Se ash ore . ▁ ▁Vis ible ▁seven ▁miles ▁out ▁at ▁sea , ▁early ▁sail ors ▁used ▁T urt le ▁M ound ▁as ▁a ▁navig ational ▁device . ▁ ▁The ▁Tim uc uan ▁experienced ▁greater ▁compet itive ▁forces ▁for ▁finite ▁resources ▁such ▁as ▁a rable ▁land ▁resulting ▁in ▁increased ▁open ▁conflict . ▁ ▁This ▁is ▁apparent ▁in ▁some ▁of ▁the ▁material ▁found ▁in ▁the ▁T urt le ▁M ound ▁location ▁where ▁it ▁occupied ▁an ▁important ▁location ▁along ▁the ▁coast . ▁Arch ae olog ists ▁have ▁recently ▁found ▁ 1 , 2 0 0 - year - old ▁pot tery ▁on ▁the ▁site . ▁ ▁Character istics ▁The ▁shell ▁m ound ▁is ▁a ▁depos it ▁of ▁refuse ▁composed ▁mostly ▁of ▁o yst er ▁shell s , ▁but ▁no ▁extensive ▁exc av ations ▁have ▁been ▁made . ▁The ▁m ound ▁contains ▁several ▁species ▁of ▁tropical ▁plants . ▁Sur ve ys ▁have ▁confirmed ▁the ▁presence ▁of ▁Amy ris ▁elem if era , ▁H eli otrop ium ▁ang ios perm um , ▁Pl umb ago ▁sc and ens , ▁Harris ia ▁fra gr ans , ▁S ider ox yl on ▁fo et id iss