"L?tschberg Erlebniszug" (L?tschberg experience train) of the BLS Stiftung (BLS Foundation) with locomotive Ae 4/4 # 251 from 1944 and four first class (used as second class) standard cars type I, is crossing the 78 meters high, 110 meters long Bietschtal viaduct with a main span of 95 meters. This impressive viaduct on the south ramp of the L?tschberg mountain line was inaugurated in 1913 with single track, but prepared for a second track, which was built from 1979 to 1985. The "L?tschberg Erlebniszug" is running once a month during summer 2018 with changing historic vehicles of the BLS Stiftung.
