Ditto Hadrian's Wall [0] in the UK. It's still impressive as it cuts across the Northern moors, but is a mass of grey stone. Back in the day, it was believed to

Ditto Hadrian's Wall [0] in the UK. It's still impressive as it cuts across the Northern moors, but is a mass of grey stone. Back in the day, it was believed to have been plastered and whitewashed, creating a stunning 70 mile long visual marker of the Northern extent of the Roman empire [0] https://en.wikipedia.org/wiki/Hadrian%27s_Wall https://en.wikipedia.org/wiki/Hadrian%27s_Wall