Buenos Aires has a subway system (the Subte) with six lines, covering the main east-west and north-south routes. Line A (the oldest subway line in Latin America, opened in 1913) runs along Avenida Rivadavia with original wooden carriages on part of its route; Line D and Line H connect the northern neighbourhoods. Fares are charged via the SUBE card, which must be purchased at stations or kiosks. The subway is fast but crowded during rush hour (8–9am, 5–7pm) and stops running around midnight.
Buses (colectivos) cover the entire city and run 24 hours. The network is extensive and fast if you know the routes; SUBE cards work on buses as well. The route numbers and apps like BA Cómo Llego (similar to Google Maps) make navigation manageable.
Taxis are metered, plentiful, and reasonably priced by international standards. Remises (private cars without meters, booked by phone) are safer and more reliable; the price is agreed in advance. Apps like Cabify work in Buenos Aires. Avoid unmarked taxis.
Walking between San Telmo, the Microcentro, and Recoleta is practical — the distances are about 2–3 km. The streets are flat. Cycling is possible using the EcoBici city bike-share scheme (registration required) and a growing network of dedicated lanes.