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Following the discovery of tin deposits in around 1440, extraction activities began in the area surrounding the present-day sinkhole. The ore was largely mined using the fire-setting method. Once the ore was removed, empty chambers (known as stopes) were left behind. The deposit site was honeycombed with such stopes, and eventually the remaining pillars were unable to support the weight of the rock overhead. The first collapses began in the 16th century. The largest then occurred in 1620, destroying large parts of the original mines, and causing a two-hectare funnel-shaped sinkhole to appear at ground level. Today, this sinkhole is 160 metres deep, has a diameter of 400 metres, and covers an area of around 12 hectares.