Villazón and La Quiaca
The train station in Villazón is about 30 minutes walking uphill from the border (only a slight gradient but in heat and rare atmosphere can be a struggle) or 4 pesos (not accounting for inflation) Argentinian pesos by taxi from the border. You can take a train to Tupiza, Uyuni and further on. Trains leave 4 times per week. The train to Oruro takes 16 hours and in Ejecutivo class (best) costs 233 bs per person. There is a 1 hour time difference between La Quiaca and Vilazón of which you should be careful.
Now, september 2013, the train runs only from Oruro to Tupiza and the line is suspended to Villazon. As you can see http://www.fca.com.bo/.
The more comfortable and faster Expreso del Sur leaves on Wednesdays and Saturdays. The more basic Wara Wara del Sur on Mondays and Thursdays.
Prices vary according to departure day and class.
Train tickets for Salón class have to be bought the day before the train leaves (but they are kind of flexible about this rule) and for Ejecutivo they may be bought the same day. Trains leave 15:30 in the afternoon.
The bus terminal in Villazón is 10 Minutes from the Border. It's a straight road from the customs into the main town - keep going ahead and you will see the bus terminal.. There are bus connections to Tupiza, Tarija, Potosí and directly to La Paz.
The bus terminal in La Quiaca is about 15 minutes walking from the border if you are fit and acclimatised to the altitude, if you have issues with heat, altitude or baggage get a taxi which should only cost 5 pesos. The taxis are old and look pretty poor but get there without hassle.
Bus companies with good reputation include FlechaBus and Balut. The trip is pleasant with great scenery. The buses are clean with toilet on board. Care is taken to protect your luggage. Safe way to travel. Avoid Panamericano as they charge a hidden "gringo tax", sell overpriced service to Salta that changes bus lines in Jujuy, and the bathrooms on their buses do not work.
If you are going into Bolivia - To walk from the bus terminal to the border - from the corner of the bus terminal , turn right on belgrano street. It's about 5blocks or less straight down to a T-junction (wider main road boulevard - Av internatcional). Turn left when you reach the t-junction of this main avenue. It's another 100m from there to the border customs ( you will pass a gas station).
Villazón is separated to La Quiaca by an international bridge with Bolivian immigration on one side and the Argentinian on the other. The border procedures are fairly easy for most tourists.
As La Quiaca is basically a boarder crossing town it is not a tourist town. It has a safe feeling. It seems to be progressing as there is a lot of building reconstruction around the centre of town. It would appear to be a town that is thriving on exports to Boliviar. At the border crossing there is an army of Bolivian people taking heavy loads of goods across the border. It is possibly easier to have the army of couriers take the goods by foot than to get the goods through custome by truck.
This border crossing can take painfully long to cross - 6 to 8 hours, and there is no shelter where you queue - remembering at high altitude the weather conditions are harsh and can change rapidly, so it is advisable to get in as early as you can in the morning!! Sometimes foreigners get shuffled through but don't count on it. The Argentina and Bolivia counters are literally side by side so don't miss them!
There are hearty and cheap menus available upstairs at the municipal market, from about Bs 8. Around the bus terminal, there is an abundance of reasonably-priced eateries. For better food you have to head to La Quiaca. Watch out for restaurants refusing to give prices, they charge a lot more if you don't agree a price beforehand. La Coyote near the bus station down towards the centre is very basic looking but has good prices. A full meal can be had for $48.
There is an abundance of cheap hostels between the bus terminal and the railway station, so accommodation will not be a problem.
Hotel de Turismo. 140 Argentinian pesos per night (October 2009) is reasonable. The standard is as good as it gets in town, close to shops as the town of La Quiaca is not too big.
Hostal Plaza is a decent, reasonably clean hotel with hot water. It's on the main square, and costs about 150 bolivianos per night for a twin. 135 for a double.
Note that there is NO access to wifi in Villazón. There is one Internet cafe that advertises it (on Calle Independencia, a couple of blocks up from the main square), but they claimed it wasn't working when we tried to use it. There are, however, several Internet cafes that charge about 3 BOB an hour. You just can't use your own computer.
There are two ATMs that take foreign cards in Villazón, both on Calle Independencia - one on the Northwest Corner of the square - Banco Unión (beware: it charges 5% on withdrawals) and one that is quite hidden, about 5 meters further up (I don't know if this one charges extra).