Alpine Club Vienna
if you are interested in hiking, walking or "only" in nice club evenings, just visit the website Protected content and perhaps show up at one of the meetings - always the first monday of the month. It is an english speaking group, about one third are Austrians.
There we have slide shows, announcements und discussions about the last and next events, and afterwards socializing in a pizzeria round the corner.
There is not any official membership in Alpine Club Vienna. Just for bigger montain-hikes a membership in one the alpine clubs is recommended because of an appropriate insurance. For the meetings no prior contact is necessary, for walks it would be nice, for some hikes it is necessary.