British icons

Prove from the text that the London Tube is the oldest underground railway system in the world.

Prove from the text that the London Tube is the largest one in the world.

Prove from the text that the London Tube map is an absolutely new type of map.

Prove from the text that the British Library is one of the greatest libraries in the world.

Prove from the text that Sherlock Holmes is one of the most famous detectives in the world.