The Weald is an area of upland that covers most of Kent. Looking north you can see the flat plain and then the sandstone ridge that runs east-west across the north part of Kent.
Iron-rich sandstone was mined in the High Weald, beginning in the Iron Age (around 2,500 years ago), while the surrounding woodlands provided charcoal for heating the furnaces. Then when the Romans invaded, they managed and expanded the iron industry to for their navy.
Then came the blast furnace – a technological advance in the late 1400s, NS the High Weald became the industrial centre of England. That went on until the ndustry declined in the 1700s, as ironmaking shifted northwards.