The beginning of the Lötschberg line is in the rail node of Spiez, where it connects with the GoldenPass line from Zweisimmen and with the Lake Thun line from major rail hubs in northern Europe, including Basel and Bern, to Interlaken. From there the line runs generally due south through the Kander valley, passing through Mülenen, Reichenbach and Frutigen, where the northern portal of the Base Tunnel is located. After the Kander viaduct, the mountain line continues towards Kandergrund and Mitholz. The line turns back to north after the loop of Mitholz and climbs out of the valley on the western flanks of the Ärmighorn. A spiral tunnel put the line back towards south, before it reaches Kandersteg, the last station on the northern approach. Two kilometres (1.2 mi) after Kandersteg, the line reaches the northern entrance of the Lötschberg Tunnel. Immediately after the southern entrance is the station of Goppenstein, in the lower part of the Lötschental valley. The line is mostly underground before it exits the latter valley and turns in an easterly direction to the southern flank of the Bietschhorn just before reaching Hohtenn Station, above the Rhone. The lines then continues in the same direction, descending towards Brig. It crosses the wild valleys of Jolital, Bietschtal, Baltschiedertal and Gredetschtal, passing through Ausserberg, Eggerberg and Lalden. The line finally ends at Brig, where it connects with the Matterhorn Gotthard Bahn from Zermatt to Disentis and the Simplon line from Geneva and Lausanne to Domodossola, and further to Milan. The southern portal of the Base Tunnel lies on the Rhone valley floor, below Ausserberg. The rest of the base line passes through Visp before it reaches Brig. The entire Lötschberg line is long and culminates at above sea level. The open-air section culminates at Goppenstein at and the northern approach culminates south of Kandersteg at . It is the highest line in Switzerland that is both an adhesion and a standard gauge railway, therefore usable by standard InterCity trains. The journey from Spiez to Brig lasts 72 minutes on the mountain line and 35 minutes on the base line.