Amazing city. And that metro system puts the London underground to shame. Trips on the Paris Metro of the same duration as what I take in London felt much shorter. This is due to the noise on the tube. The tube screeches and squeals through the heat whereas the trains I used in Paris ran on tyres, and the effect is a smooth quiet ride. The Metro felt much cleaner, everything on the tube is coated with a layer of carcinogenic brake dust. Combined with the heat, no wonder my stress level on the tube is so high.