We went to a public viewing platform to witness a "blast". There were in fact 2, the first on the left of the picture and the second in the centre of the "plateau". It's very hard to get an idea of scale in the photo, but each stope (step-like drop) is approx 30 feet. My sons had a bizarre debate about "If you uprooted and inverted Ayres Rock, would it fit into the hole left by this open mine?". Answer, "Probably!".