Sønderborg is the closest regional train station accessible from all over Denmark with direct trains from Copenhagen and connections from Northern Jutland and Odense.
Hotel 6400 is less than 3km from the train station, about 10 minutes in a taxi.
When coming from the Motorway:
Exit European motorway E45 at junction 73 Kliplev, and take the A8 towards Sønderborg. Remain on the A8 after the bridge over Als Sound, and at the roundabout, take the first exit.
Continue for 3.4 km then turn left on to Solglimt, then first right and then first left, continue 100 m and you have arrived at Hotel 6400.