Public Transport:
The most sustainable option for arrival is by train (coming from Villach) to Hermagor. From Hermagor you then reach Tröpolach by station shuttle as well as by bus / ski bus.
Alternatively, there is also the possibility to arrive by bus from the direction of Kötschach-Mauthen or Villach to Hermagor or Tröpolach.
From Tröpolach, you then take the Millennium Express up to the mountain station – which is located in close proximity to the mountain station of the Madritschenbahn.
Details at - Nassfeld mobility info and Kärntner Linien route planner
Arrival by car:
Via the B111 (Gailtal road) to Tröpolach – from there via the B90 (Nassfeldpass road) towards the state border. Turn right onto the road to the valley station of the Madritschenbahn 300 m before the border from the B90.
Or alternatively in Tröpolach, turn right from the B90 onto the parking lot at the valley station of the Millennium Express.