From a nice trail following the southern Lötschberg ramp of the line through the alps, which connects Spiez in the Bernes Oberland with Brig Valais.

The trail follows a former steamer line trough tunnels, which was used during the construction of the Lötschberg line. Here a view of the impressive Bietschtal viaduct, which can be crossed by hikers.

See  http://en.wikipedia.org/wiki/Lötschberg_railway_line