That's what they call 'emptied Spain', or the Ibearian Lappland, due to its low population and population density.
It is in no small part due to the effect of Madrid and the radial infrastructure system, that basically drives you through Madrid to get anywhere else. Between that and the fact that Madrid is a sort of tax haven within Spain, big companies, and therefore massive numbers of jobs tend to flock around it, and that's how you get that island in Madrid surrounded by nothingness until you get to the coast.
That and Spain is relatively underpopulated. It's larger than Germany but only has about 60% of the population, iirc.
Speaking of Germany, it's interesting to see how East Germany is a low plain with a towering mass in its midst which is Berlin.