Rennweg is located in the Katschtal, the upper part of the valley of the Lieser River, a tributary of the Drava. Its location on the Katschberg Straße (B99) highway near the Katschbergtunnel, connecting the states of Salzburg and Carinthia, gives its citizens
and travelers access to the Tauern Autobahn (A 10). The Katschberg mountain area is considered one of the largest skiing resorts in Carinthia bringing much of Rennweg's reputation.