Which city has the world's oldest subway system?

Which city has the world's oldest subway system? London. The Metropolitan Railway opened in London on 10 January 1863, creating the world's first underground railway and the foundation of today's London Underground.

The original route ran from Paddington to Farringdon, largely using the cut-and-cover method: workers dug a trench, built the railway, and covered it with a road surface. About 40,000 passengers used the line on its first day, showing how urgently Victorian London needed relief from severe street congestion.

A common mix-up is confusing the oldest underground railway with the oldest deep-level “Tube” railway. London’s first deep-bore electric line, the City & South London Railway, opened in 1890. The London Underground is also not one single railway built at once; it grew from several separately operated companies that were later unified under London’s transport system.