On geological timescales, that makes no odds. Nothing built of stone will survive natural weathering over millions of years. Mountains don't survive it. Concre

On geological timescales, that makes no odds. Nothing built of stone will survive natural weathering over millions of years. Mountains don't survive it. Concrete won't survive it either, even modern reinforced concrete (actually, our modern reinforced concrete won't last as long as the concrete the Romans used, and their concrete might actually outlive lots of ours).