Arzachena is a town and comune in the province of Olbia Tempio, northern Sardinia, Italy. Arzachena lies half way between the original Costa Smeralda resort and Porto Rafael, both founded in the late 1950s. After Olbia and Tempio Pausania, it is the third largest commune in Gallura by inhabitants. The frazione of Porto Cervo is the main resort area of Costa Smeralda for summer tourism, which has replaced agriculture as the local main economical source starting from the 1960s.