San Salvador has no surprises, this translating as the 'Holy Saviour'.
Apopa is a delicious description of this area and describes 'a place with mist'.
Antiguo Cuscatlan, known locally as simply Antiguo, derives its first element from the Spanish for 'old' and the latter from the indigenous Nahuat for 'jewelled city'.
Metapan is a Nahuatl name meaning 'river of the maguey',
San Miguel is another of Spanish origin, here the name originally being San Miguel de la Frontera and translating as 'Saint Michael of the Frontier'.
Santa Tecla was founded by the Spanish as Nueva San Salvador or 'new Holy Saviour' after the capital had been destroyed by an earthquake in 1854. In 2003 the name returned to Santa Tecla, the latter the original name of this region when settled by the Spanish, Saint Thecla an early Christian saint said to have been a follower of Saint Paul two thousand years ago.
Berlin is, somewhat predictably, a name transferred from the more famous example in Germany - and if you want to know the toponomy of the German city look back at
Ataco is an indigenous Nahuatl word meaning 'high place of springs', obviously a sensible place to found a settlement as it has a source of fresh water, would be above the flood plain, and easy to defend.
Note the spellings of the places are English as the piece is written in English.