The Windows That Never Open
A blind arcade is a wall decoration that looks like a series of arches but is actually solid stone. These fake openings serve no functional purpose and act purely as ornamental skin for buildings.
Architects use these false arches to break up the monotony of large, flat masonry surfaces. By carving the illusion of depth into a solid wall, they add texture and rhythm to otherwise plain stone faces. You can spot them on ancient cathedrals and historic palaces throughout Europe. They transform functional walls into canvases for intricate shadow play and artistic design.
Source: Blind arcade