You will need a valid passport and will have to fill in a landing card on arrival and you will be given a stamp for stays of thirty, sixty or ninety days. Staple your duplicate of the landing card into your passport, next to your entrance stamp, as you'll need it to leave the country and police may check it. If you do lose it, it's rarely a serious problem, but you'll have to fill in a new form at the border control. On entering the country, you will also be given a customs declaration form . Duty is not charged on used personal effects, books, and other articles for non-commercial purposes, up to the value of $300. Make sure you declare any valuable electronic items such as laptop computers, as customs officers can be suspicious that you may be bringing them into the country to sell.

You can extend your stay for a further sixty days by presenting your passport to the main immigration department: Direccion de Migraciones , at Av. Antartida Argentina 1350, Retiro, in Buenos Aires (tel 011/4312 3288 or 4311 4118).

Alternatively, you could try leaving the country (best to do so for at least 24 hours, perhaps by making the short hop to Colonia del Sacramento) and returning to get a fresh stamp. This usually works, but is frowned upon if done repeatedly, and the provision of an extra stamp is totally at the discretion of the border guards. Some people manage to stay for a year on tourist visas alone, by using a combination of these brief trips abroad and extensions ( prorrogas ).

When leaving the country, you must obtain an exit stamp . At certain controls (particularly in the north of the country, where there is a lot of cross-border Mercosur traffic), it is often up to you to ensure that the bus driver stops and waits while you get this - otherwise drivers may not stop, assuming that all passengers are Mercosur nationals, who don't need stamps. Not getting your proper stamps will leave you facing fines and considerable hassle later on in your trip. Be aware that in some places (for example, Clorinda), your Argentine exit stamp is actually given on the far side of the border, but check this with the driver.

Visas for work or study (both valid for a maximum of twelve months) must be obtained in advance from your consulate. Students will first need to obtain a letter from their proposed place of study, which offers a place on a course and has been legalized by the Argentine Ministry of Education. This must be presented to your respective consulate, along with medical and birth certificates and three photos. The visa costs approximately $100, plus around $50 for additional paperwork fees (processed in approximately a week). For a working visa , you can either get your prospective company to approach immigration in Argentina with the contract and arrange for an entrance permit to be sent to your respective consulate, or take your work contract, authorized by an Argentinian public notary, to the consulate yourself and the consulate will obtain the work permit from Buenos Aires. Expect the process to take at least a month. Work permits cost $200, and the visa itself another $100. Both student and working visas can be extended only in the Direccion de Migraciones.

Visitors are legally obliged to carry their passports as ID . You might get away with carrying a photocopy, but don't forget to copy your entrance stamp and landing card as well. In the majority of cases, this is acceptable to police, but getting a copy certified by a public notary increases its credibility.