Water thunders down through the black, glistening walls of the Liechtensteinklamm gorge in St. Johann im Pongau, Salzburg province — one of the longest and deepest slot canyons in the Alps — captured here in a strikingly dramatic real-photo postcard that leans into the vertiginous geometry of the wooden walkway railing against the roaring cascade beyond. The Liechtensteinklamm, carved by the Großarlbach river through Triassic limestone, was opened to tourists in 1876 and named for the ruling House of Liechtenstein; by the postwar era it had become one of the most photographed gorge experiences in Austria. The reverse was sent to "Herrn u. Frau [H]enry Kirchman" (first names: Henry) at Wien XV, Pelberstrasse 104, bearing a lively hand-written message describing a beautiful excursion "durch die Liechtenstein-Schlucht" and sending greetings. A purple Liechtensteinlamm visitor's stamp — featuring an edelweiss — adorns the message side alongside the Austrian 30-Groschen "Woman Hiker" stamp postmarked at the gorge's own postal station.