Rauðhólar

This guide to Rauðhólar in Reykjavik starts with a tidy wartime number, the ninety-five thousand cubic meters of red gravel the British army recorded hauling away to pave the city's new airport runways. You'll hear why that figure has long stood in for the whole story of this cluster of pseudocraters, formed some five thousand years ago when lava flash-boiled a shallow lake into steam, and why the arithmetic stops adding up once you count how much of the original hundred and fifty cones is actually gone. It follows the quieter, decades-long quarrying that continued long after the soldiers went home. Look at the mounds sliced clean through as you walk among them, their red scoria exposed like a cut cake.