The Castlestrange stone is located in the grounds of "Castlestrange House" near Athleague in County Roscommon, Ireland.
[1] It is a granite boulder decorated with flowing spirals in the La Tène style, dating from the Iron Age period between 300 BC and 100 AD.
[4] All four stones lie on roughly the same line connecting them on a map of Ireland.
The use of the stones is not known but it is assumed they served some religious or ritual purpose.
This article relating to archaeology in Ireland is a stub.