Klosterneuburg, 30 minutes from Vienna by S-Bahn, holds the Verdun Altar in Stift Klosterneuburg: 51 medieval enamel panels completed in 1181 by Nicolas of Verdun, one of the most significant medieval artworks in Austria. The Augustinian monastery itself, founded in 1114 by the Babenberg margrave Leopold III (Austria's patron saint), has operated continuously since and produces wine from the surrounding Danube valley vineyards. The imperial quarters begun by Charles VI in the 18th century convey the ambition of a project that was never finished. Day trip from Vienna; the monastery tour covers the altar, the imperial rooms, and the wine cellar.