People arriving at Paris’s Orly Airport for the 2024 Olympic games will be able to take an underground train straight to Saint-Denis where most of the Olympic action is taking place.

It's thanks to a line extension that opened on June 24. And that is just the ‘hors d’oeuvre’. The Grand Paris Express is a metro expansion on a massive scale whose aim is to transform the city from a normal-sized European capital to a metropolis the size of London.

What could it do for the Parisian, and French, economies?

(Image: Saint-Denis–Pleyel station in Paris, France. Copyright: Société des grands projets / Kengo Kuma & Associates / Sylvain Cambon)

Presented and produced by John Laurenson