Which city’s subway/metro system is represented in the map?

Metro map

Madrid
🙂 You’re right! The Madrid Metro was the 7th longest in the world as of 2017.
Mexico City
Oops — try again! Learn about the Mexico City Metro.
Paris
Nope, give it another shot! Learn about the Paris Metro.
Barcelona
Guess again! Learn about the Barcelona Metro.
London
Sorry, want to pick another? Learn about the London Underground.