This one, they think, was caused by the lightening bolt. it's very foresty up there, lots of pine and eucalyptus, which go up very quickly.
The government has recently put a ban on any more eucalyptus forests, as the paper industry is in decline. We have a forest behind us

which won't be cut down for a few more years yet.
I keep an eye on a site which gives up-dates of where the fires are, in the whole of Portugal, about once an hour.