Madrid's Metro is one of the oldest and most extensive in Europe — fast, clean, and safe, with twelve lines covering the city and airport. Trains run from 6:00 a.m. to 1:30 a.m. A single ride is €1.50–2.00; the ten-trip Metrobús ticket (€12.20, shareable) is the best value for visitors. The Metro connects both Barajas airport terminals directly to the centre.
Buses serve every corner of the city at any hour; after midnight, night buses (buhos) leave from Plaza de Cibeles. Suburban trains (Cercanías) run from Atocha, Chamartín, Nuevos Ministerios, and Recoletos stations and are the best way to reach nearby towns like Toledo, El Escorial, and the Sierra de Guadarrama mountains (Cercedilla, Navacerrada, Cotos) for skiing in winter.
Madrid's centre is walkable — distances between the main sights along the Paseo del Prado, Plaza Mayor, and Puerta del Sol are all under fifteen minutes on foot. Taxis are plentiful, metered, and not expensive by European standards. App-based services (Uber, Cabify) are widely available.