This uber-awesome postcard has the following text on the back:
St. Bernhard-Zwinger Zwing-Uri
To the right of the text, there is a stamp for Hotel Stern & Post, Amsteg. Additionally, someone wrote the following in pen: "July 25, 1963. Lucerne, Switzerland." (The postcard itself was never mailed.)
Flüelen is a small municipality, with a population of about 2,000, in Switzerland. I guess it was once home to a St. Bernard kennel. (Zwinger is a German word that translates to kennel.) The St. Bernard is, of course, a huge breed of dog that is famously known for its use as a rescue dog in the Swiss Alps.
(The image we have in popular culture of a brave St. Bernard with a small barrel of brandy around its neck is, by the way, a historical fabrication, according to Mental Floss. But, brandy barrel aside, the dogs rescued many travelers over the centuries. Barry der Menschenretter (1800–1814) was one of the most famous St. Bernards in this respect.)
Silenen. Hotel Stern and Post is one of Switzerland's oldest hotels, dating to the 14th century. You can learn more about it on the English-language version of its website.
Or, if you'd rather just look at the St. Bernards in more detail, here you go...