Underground Station Near The Opera Building, Madrid, Spain Editorial Photo

Continental Europe’s most extensive underground rail transport network, the Madrid Metro, has transformed the life of Europe’s third-largest city. Financing this project initially met with stiff resistance: scepticism was voiced about the logic of building an underground rail network in what was then a small city with little road traffic. It was the Spain’s King Alfonso XIII personal donation of one million pesetas roughly £500,000 in current value that sent persuasive signals to investors. The operating company set up in 1920 was duly christened Compañía Metropolitana Alfonso XIII, now renamed Metro de Madrid.