What is an ISA port?

The city can be said to have come into existence soon after 1923 when John Campbell Miles discovered a rich seam of silver-lead on the western edge of the Cloncurry field. Copper and zinc are also mined. Copper, lead and silver are smelted on site, with anodes and zinc concentrate being transported 900 km to the city and port of Townsville on the east coast. The mine is the most significant landmark in the area, with the stack from the lead smelter (built 1978), standing 270 m tall, visible from all parts of the town.