Hallstätter See or Lake Hallstatt is a lake in the Salzkammergut, Austria. It is named after Hallstatt, a small market town in Austria, famous for its salt mining since prehistoric times and the starting point of the world's oldest and still working industrial pipeline – for brine to Bad Ischl and further to Ebensee.
Since about 1970/1980 the only ship-mail-line of Austria crossed the lake from the railway on the east shore to the town in the west. In winters the road on the west shore tended to be blocked by high snow or the risk of avalanches. When the ice on the lake was thick enough, a sled pulled by men or horses, later a motorized track vehicle was used to transport mail and persons.
Wikipedia https://en.wikipedia.org/wiki/Hallstätter_See
Address 4823, Austria
Coordinates 47°34'29.823" N 13°39'31.413" E