The municipal area covers the valley of the Vellach creek, which runs in north–south direction from the heights of the Kamnik-Savinja Alps and the Karavanke range down to the Drava River.

Eisenkappel-Vellach consists of the main locality Bad Eisenkappel and several smaller settlements located in lateral valleys,[3][4][5] subdivided into the Katastralgemeinden of Bad Vellach (Bela), Blasnitzen (Spodnja Plaznica), Ebriach (Obirsko), Eisenkappel (Železna Kapla), Koprein Petzen (Pod Peco), Koprein Sonnseite (Koprivna), Leppen (Lepena), Lobnig (Lobnik), Rechberg (Reberca), Remschenig (Remšenik) and Trögern (Korte).

According to the 2001 census, 38% of the population are Carinthian Slovenes, distributed over the 15 localities as follows: The Seeberg Pass was already part of a Roman road in the Noricum province from 15 BC onwards.

The Eisenkappel citizens had to rely on forestry and summer tourism around several mineral springs, promoted by the opening of the Vellachtalbahn narrow gauge railway line in 1902.

In the late days of World War II the remote Peršman farm in Koprein Petzen was a strongpoint of the Slovene Partisans, the only ever-existing Anti-Nazi military resistance of Austria.