This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
CHNB Schweizer Bildernbdigpage.tif de Schweizer Bilder Teufelsbrcke und St Gotthardtunnel fr Schweizer Bilder Le Pont du Diable et le Tunnel du St Gotthard en Schweizer Bilder Devil's Bridge and St Gotthard Tunnel Institution Swiss National Library nbdig Lauterburg Emil Public domain PDold Swiss National Library CHNB Schweizer