We have an eyewitness account of the 1646 eruption in the form of a letter from the governor of Tenerife, Alonso de Yclan y Valdès, to the king of Spain. I consulted the copy in the British Library; it was almost like reading the news.

On my morning walk there is a point from which I can see the sulphurous fumes pouring from the Masaya volcano. On the lip of the crater, although not visible from my viewpoint seven kilometres away, is a large wooden cross. It occupies the pinnacle on which a similar cross was first placed in 1529 after the Spanish conquest, by the friar Francisco de Bobadilla. He climbed the volcano in what is now Nicaragua, looked down into its fiery crater, decided it must be the entrance to hell and had the cross put up to keep it firmly shut. Soon afterwards, a more avaricious and foolhardy friar, Blas de Castillo, is said to have climbed down into the crater and, lowering a metal bowl on a long chain, extracted what he thought was molten gold. It quickly turned into an uninspiring lump of black lava.