74. Top section of the wall at Intxur viewed from inside the enclosure.© Xabier Peñalver

Once the right site had been chosen, the inhabitants would build a series of large defensive structures to protect the area within which they would erect their homes and sometimes grow crops and graze cattle.

Using stone and earth, as well as wood, they marked out spaces of different areas with walls, fosses and banks. Many of these constructions have survived spectacularly to the present day. These defences often ran right round the enclosure, and in some cases there were even parallel walls or fosses. Any natural defences would be completed with structures painstakingly erected by the inhabitants. In Intxur, the defensive walls were over 1500 metres long.

75. Section of protohistoric wall.© Xabi Otero

Planning and building these structures must have required specialised labour, as well as a developed collective organisation and a considerable amount of time. However, we do not know for certain whether their only function was to defend the settlement against possible enemies; given the monumental nature of these constructions, they may also have been intended as a show of power or prestige to other groups in the area or from further away.

76. Fosses and walls played complementary defensive functions at the Intxur settlement.© Mugarri S.L., Xabi Otero, Grafismo

The fosses in Intxur are particularly striking, with depths of up to four metres in some sections and a total length of 650 m, surrounding the twin peaks of the hill.

In general, the walls consisted of two dry stonework stretches made of stones of different sizes. The are between was filled with gravel and earth. They are between 2 and 2,5 m. wide and up to 2 m high and may have been surmounted by timber structures to make them even more effective. On occasions, rocky outcrops were included in the defences (Intxur, Buruntza). This reduced the amount of work involved and made the construction sturdier. In all cases they seem to have prepared the land first, to make the walls more stable and help prevent them collapsing down the steep sides of the hills.

78. Inner curtain of the wall at Basagain adjoining a dwelling.© Xabier Peñalver

77. Plan and elevation of the wall at Intxur.© Xabier Peñalver

It is not easy to identify the entrances to these enclosures. The gateways have largely been obscured by the passing of time and painstaking excavation work will be needed to find them. However, the location of the entrances was closely related to the relief of the area to be defended and the design of the defence itself.