Avoid people on the street who offer to change your currency to pesos; head to a bank instead. Banks are generally open weekdays 7-1 and 4-8. For ATMs, look for the maroon banelco sign of Argentina's largest ATM network. You can use your Plus or Cirrus card to withdraw pesos. Traveler's checks aren't recommended in the Northwest. Few places accept them, and with ATMs so easy to find, there's little need for them. Outside the major towns, many businesses don't accept credit cards and cash is sometimes the only option.