— Block caving is more cost-productive than any other underground mining method, but only works in certain geological situations - mainly, where there is a massive ore body (large in all three dimensions) that readily collapses under its own weight and breaks into small pieces. Block caving does not work well in very hard rock, and is unsuitable for more complexly shaped or horizontal ore bodies. Water management can become a major issue, especially post closure, as groundwater percolates through the massively disrupted zone.