Iquique is a city in Chile in Region I de Tarapaca.
If you are looking for a ride to cross the border to Argentina or Peru, many trucks departs from Zofri (Zona Franca de Iquique) to Peru, Bolivia or Paraguay.
The easiest way to Hitch a ride south is to go to the exit of Iquique (la salida) which is called bajo molle (micro bus 4,6, or 17 from líder store or taxi colectivo). From here the route 1 highway starts and goes down the coast towards Tocapilla or Antofagasta with the advantage of seeing some beaches instead of neverending desert for a while... Miriam did that but there was literally no traffic on that road, exept for Pickups going to the next power plants and mines. The first truck that looked like it was going all the way south to Tocopilla did pick her up, after approx. 5 hrs of waiting. No matter the hassels to get to Ruta 5, it might still be quicker and easier. There are buses though in case you want to give up.
The alternative is to get a bus to alto hospicio and ask to get off at the autopista. From there you can get a ride to the route 5 highway and choose to go north or south up or down Chile.
Mind of a Hitchhiker took the micro to Alto Hospicio and got a ride to the last gas station on this highway in early 2017. There she found another ride to Humberstone from where she found a ride up north the Ruta 5. This was quite a hassle and could have been done much easier. Ask for Huara instead if you're going north.
Other useful info
There's a random giant sand dune in the middle of the city if you're looking for a spectacular playground.