The increasing importance of iron mining and metal-working throughout the Basque Country after the end of the Middle Ages explains the creation and geographical distribution of the rent-houses (renterías or casas-lonja). These were sites were the material was stored and sold and where crown taxes were paid. Facilities and instruments were provided for loading, unloading, weighing and storing both the raw mineral and the processed and semi-processed iron.

Because of the function of these buildings-to take payment of duties on the iron-they were distributed throughout Gipuzkoa, at sea and river ports from Hondarribia and Errenteria in the east, to Alzola in Elgoibar in the west, by way of Donostia-San Sebastian, Hernani, Arrazubia in Aia and Bedua in Zestoa, as well as at important mining and marketing sites from inland areas to the sea.

One of the renterías about which we have most information is Bedua. The local nobility had enjoyed the rights to charge the crown duties on iron trading and mining since the Middle Ages. Bedua was a loading point for the Urola estuary, from where the iron was transported along the paths leading up the valley to forges and inland towns. On the simple quayside, the ore imported from Bizkaia was unloaded and the products of local ironworks were stored. Although the site has changed over the years, the large administrator's house built by the owners in the late seventeenth century still stands. The building-cubic in shape-is in the classical style. The loggia or triple upper arcade faces out onto the open area where the raw and manufactured iron entering and leaving the river port was tallied.