The Sistema de Transporte Colectivo (STC) is the metro system serving Mexico City. It is one of the largest and most extensive urban transit systems in the world, consisting of 12 lines that cover over 200 kilometers. The STC provides a fast and efficient means of transportation for millions of passengers daily, helping to alleviate traffic congestion in the city. The metro system began operations in 1969 and has since expanded significantly. It features modern trains, numerous stations, and a variety of services, including accessibility options for people with disabilities. The STC is a vital component of Mexico City's public transportation network.