... are respectively the fourth, sixteenth and eighth biggest towns or cities in Chile.
La Serena (spelt wrong in the question) is a popular beach resort, about 250 miles north of the capital, Santiago. It's Chile's second oldest town, after Santiago. Greater La Serena had a population of approximately 400,000 in 2012.
There are also smaller towns called La Serena in Spain and Colombia.
Calama is in the Atacama Desert, and one of the world's driest cities. It's about 800 miles north of Santiago, and 300 miles from the border with Peru. It had a population of 147,886 in 2012.
Talca is an important economic centre, about 160 miles south of Santiago. In 2012 it had a population of 201,142.
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