Panther turrets, from battle damaged and retired vehicles along with specially manufactured ones, were also mounted in fixed fortifications by German army. Turrets (mechanically traverseable) were mounted on concrete emplacements (Pantherturm III - Betonsockel - concrete base) or welded steel boxes (Pantherturm I - Stahluntersatz - steel sub-base), which housed the ammunition storage and fighting compartment along with crew quarters. Such emplacements were located in fortifications of Atlantic Wall, West Wall, Gothic Line, Hitler Line (one of those was located at Piedimonte in Monte Cassino area) and in the East (approx. 12 in Berlin). Total of 268(280) turrets were installed as of March 26th of 1945.

Some details you can find here:

http://forum.panzer-archiv.de/viewtopic.php?t=6068
http://www.odkrywca-online.com/pokaz_watek.php?id=135191
http://rofe.19.forumer.com/viewtopic.php?p=4685
http://www.orasoft.net.pl/~leszek.ch/e_pt.htm

Please find some pictures below.