[2] In Karrantza is located the sanctuary of Venta Laperra, the oldest of the entire Basque Country, with several forms of Paleolithic art.

There is evidence of ancient pastoral activity, as well as art forms belonging to hunter-gatherers from the Neolithic and the Bronze Age.

[2] The oral traditions tells of the presence of Romans in the lands of the valley, which were interested in the exploitation of galena from the Ubal mountains.

Karrantza is located in the westernmost part of the Enkarterri region and is the largest (by area) of all the municipalities of Biscay.

Karratza is 54 kilometers away from the head of province Bilbao and limits at north by the autonomous community of Cantabria, at east mostly with the Cantabrian exclave of Villaverde de Trucios, and the Basque municipalities of Turtzioz and Artzentales, at south with the province of Burgos and at west with the tiny municipality of Lanestosa and the Cantabrian community.