Ezeiza International Airport: For central Buenos Aires, use the Tienda León coach rather than an unmarked airport taxi: it is the straightforward, fixed-price option, typically about 45–70 minutes depending on traffic, with a city-terminal transfer if needed. Expect roughly US$30–40 equivalent for a car/transfer; fares in pesos change too fast to treat online ARS figures as reliable. The bargain option is colectivo 8, but allow around 90 minutes or more and use it only if you already have SUBE/contactless payment and light luggage.
Aeroparque Jorge Newbery Airport: This is the convenient airport: it is about 20–30 minutes by licensed taxi or Cabify/Uber to Centro, Recoleta or Palermo when traffic behaves. For a cheap option, colectivo 33 runs via the Costanera toward Retiro, Plaza de Mayo and San Telmo; some line 8 services connect Aeroparque with Retiro. Pay by SUBE or contactless card—do not count on cash.
Retiro railway station: The arrival point for long-distance trains from Córdoba, Rosario and Tucumán. It is in the northern edge of Centro: use Subte Line C from Retiro for Constitución and central connections, or a short licensed taxi/rideshare to Recoleta or Palermo. Keep bags close outside the station; this is a transport hub, not a place to linger.
Constitución railway station: The terminal for trains from Mar del Plata and Bahía Blanca. Subte Line C links Constitución directly with downtown and Retiro; a taxi or Cabify is the sensible last leg for San Telmo, Palermo or Recoleta. Long-distance rail is limited and not a substitute for Argentina’s extensive coach network.