It consists of the four Katastralgemeinden: Arriach, Innerteuchen, Laastadt, and Sauerwald.
Situated within the Nock Mountains range of the Central Eastern Alps, about 20 kilometres (12 miles) in the north of the city of Villach, Arriach houses the geographical centre of the state of Carinthia. The economy of the commune mainly depends on tourism.
According to a 2001 census 68.8% of the population were Protestants, which is the highest percentage of all Carinthian municipalities. Therefore, the Four Evangelists parish church, erected in 1903, is the largest Protestant church building in mainly Catholic Carinthia. Furthermore, Arriach's coat of arms depicts an Eucharistchalice and a Luther rose.
A smaller Catholic church dedicated to Sts. Philipp and Jakob from about 1200 stands nearby. Arriach also features several historic rustic log homes preserved in quite good condition.