10 Most Extensive Metro Systems In The World
There are approximately 160 metro systems in 55 countries worldwide. Sometimes referred to as subways, U-Bahns or undergrounds. With features like heated seats, WiFi access, and art-filled stations, metro systems sometimes become the attraction itself rather than just a way of transportation. The metro system with the longest route length in the world is in Shanghai; the busiest one is in Beijing and the one…