Menhir

[Sarah]

A large stone set upright in olden times as a memorial ormonument. Many, of unknown date, are found in Brittany and throughoutNorthern Europe.

[Vania]

a tall stone put in a vertical position by people in prehistoric times (= the period before there were written records) :

[Julene]

A tall upright stone of a kind erected in prehistoric times in western Europe.