Here is an overview of Mikwaot in Vienna:
Tempelgasse 3, 1020 Vienna Tel: +43 1 2169973
Entrance at Czerningasse 4, 1020 Vienna
Opening hours: From sunset until 45 minutes after Tzet Hakochavim, or until 7:00 p.m. in winter.
Erev Shabbat and holidays: Only at Tzet Hakochavim. By appointment only.
Motzaei Shabbat and holidays: Winter: 1 hour 30 minutes after the end, for one hour Summer: 1 hour after the end, for half an hour
In an emergency, please call: 0676 848044478
* Tzet Hakochavim means that three stars are visible. The exact times can be found at: http://www.myzmanim.com/day.aspx?askdefault=1&vars=62453870.
Rabbiner Schneerson Platz 1, 1020 Wien Tel: +43 676 8487 55206
Fleischmarkt 20-22, 1010 Wien Tel: +43 /1/ 5125262