, Port Pirie is the locality of the largest lead smelter and refinery in the southern hemisphere; a lead smelter has been there since the 1880s. The owner since 2007, Nyrstar, is the city's main employer., and high blood lead levels in the local population are an ongoing concern. The Stack, which can be seen kilometres away, is 205 metres tall, and is the tallest structure in the state. In 2006 Zinifex formed a joint venture with Umicore to create Nyrstar, which owns the smelter, with the intention that it would eventually be an entity separate from the parent companies.