Llanymynech Hill is one of Wales' earliest mining sites. Evidence suggests that copper was mined and smelted here in the late Bronze Age, and that ores were used to make bronze weapons and other implements. The hill above Llanymynech is crowned with an extensive Iron Age hillfort, which extends over 57 hectares, and surrounds a cave opening known as the Ogof. The size of this hillfort is probably explained by the presence of the copper mines. The hillfort would have served as protection for the mine, and housed the labourers employed in the extraction of copper.