I was misled by (the spanish language) Wikipedia :) , you're right, it talks about the heart shape and everything. https://es.wikipedia.org/wiki/Metro_(sistema

I was misled by (the spanish language) Wikipedia :) , you're right, it talks about the heart shape and everything. https://es.wikipedia.org/wiki/Metro_(sistema_de_transporte)#Terminolog.C3.ADa https://es.wikipedia.org/wiki/Metro_(sistema_de_transporte)#... I can personally confirm that in Buenos Aires it's called Subte and the word Metro is used nowhere in Argentina or Uruguay.