Otto Wagner’s viaduct now houses trendy stores, boosting values tremendously. This transformation has inspired others nearby, for instance Ernst Mayr’s 2003 design of the Hauptbücherei (main city library), a striking ship-like building with Vienna’s largest flight of stairs located across from Roland Rainer’s 1958-era Stadthalle (city hall) and the Skywalk, a footbridge connecting the once separated neighborhoods. To best appreciate Silja Tillner’s revitalization concept, join a tour offered by the Az W.