One of the main characteristics of the Basque soil is (was) its rich content in high quality iron. Up to the XVI century, there were around 300 foundries producing iron for all of Europe. Nowadays, it still plays an important role in our present industrial activity. At the very beginning, the foundries were located on top of the mountains and they used the wind as the main force to produce iron, using coal as the source of heat (in an extreme anti-economical way). Soon they found out that it made more sense to have the ironworks by a water stream, and so “modern” foundries were established in many Basque towns.
I´ve been to two of these foundries, that have been recently restored . You can visit them (visits also available in English) in order to see “live” how iron was formerly obtained, the historical reconstruction is very well performed and what you see is probably very close to what it really was. One of them is near Bilbao, in Muskiz (Bizkaia), Ferrería El Pobal, www.elpobal.com (this link will redirect you to another page available in English)- press here for a 4´youtube video of a visitor-. You can also see how they got flour with a water mill. It´s cheap and very interesting, kids find it amusing.
The other one is located in Legazpi, Gipuzkoa, where there formerly were 7 foundries. This one is Ferrería Mirandaola, on this link (not the best of webs, but it´s in English too), located in the middle of a beautiful park where you can enjoy the incredible landscape surrounding it.