The "U-Bahn" is a rapid transit system found in several German cities, most notably in Berlin. It operates underground and above ground, providing efficient transportation for commuters and tourists alike. The system is known for its punctuality and extensive network, connecting various neighborhoods and key locations within the city. Trains on the U-Bahn run frequently, making it a convenient option for daily travel. Each line is identified by a letter and color, helping passengers navigate easily. The U-Bahn is an essential part of urban life in cities like Munich and Hamburg, promoting sustainable public transport and reducing traffic congestion.