Interregio 1137 of the Rhaetian Railway from Chur over the Albula line to St.Moritz, with Ge 4/4 III # 647, is leaving the 300 meter long Mistail tunnel and crossing the 32 meter long Mistailtobel viaduct in the Schin gorge between Solis and Tiefencastel. Above the train, not visible for the passengers, is one of the oldest preserved churches of Switzerland, St. Peter of Mistail from the 9th century. The church of St. Peter Mistail is a Carolingian triple apse church in Alvaschein (municipality of Albula/Alvra) and the only unbuilt triple apse church in Switzerland. The exact date of origin is not known, but it is assumed to be around the year 800. Mistail is indirectly mentioned in the year 823 in a letter of complaint from Bishop Victor of Chur to Louis the Pious. The monastery is first mentioned in a document in 926 in a deed of donation from Henry I to Bishop Walde. The fact that the monastery is named and has the same patronage as the convent in Cazis leads to the assumption that Mistail was founded by the convent in Cazis.
