Ah - more. ""If you go back to 1750, the area was completely different there were dozens of engine houses and hundreds of shafts in the area, which probably looked a bit like a desert.

"It would be something almost unrecognisable, probably more like a foreign country than what we know.

"As mines closed, many put very large bits of timber across shafts and backfilled them, thinking this would be safe.""

So builders aren't obligated research the property, look at those old maps, before starting construction?