The archaeologists may turn up other unexpected finds as they dig back through soil packed down over centuries.

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When weather is drier, the rats seem to love living under the soil, and can dig deeper than water can seep.

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In some places, you would have to dig down over 100 meters before you found soil again.

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Even developing countries with vast quantities of coal under home soil will find themselves unable to dig it out quickly enough to meet demand.

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If we managed to dig a several hundred foot vertical shaft and the soil was feeling generous, not collapsing inward and waiting for us to build the wall, the challenge of casting this concrete would still be great.

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This is achieved due to its soil, which sits on a gravelly plateau where the vines have to dig deep to extract the nutrients.

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