This is the main room of the palace. It was here that the owners received their guests, and here we see the most important surviving elements of the manor’s interior decoration. The room is large, yet it has only two small windows, resulting in limited natural light—hence its name, the „Semi-Dark Hall.” Polychrome analysis has revealed the full extent of the palace’s original décor. As you can see, the ceiling is ornate, although only half of it has been fully uncovered; the other half was in a state of structural failure during restoration—the plaster had crumbled away—so only the central section was preserved. Features revealed include a wall frieze, geometric ceiling patterns, and floral ornaments set within stylized frames. Rosettes and acanthus leaves—a motif representing the extraordinary beauty of distant lands, imagined by artists who had never actually seen the plant itself—create a mysterious and evocative atmosphere in the room. These are hallmarks of Romantic Classicism, reflecting the architectural fashion of the era in Lithuania. In the corner stands a large stove made of white ceramic tiles, which heated more than just this room. Beneath your feet lies an oak and ash parquet floor featuring a geometric pattern; restorers replaced only small, worn-out sections, meaning the floor remains largely original.

Today, this hall serves as a venue for concerts, meetings, and conferences. It hosts exhibitions as well as educational and tasting programs. The small rooms adjacent to this hall—whose wall paintings perhaps depict the giants who piled up the Kupiškio hillfort while puffing on their pipes—likely served as a smoking room; indeed, the compositions above the doorways (known as „supraportes”) feature depictions of pipe smokers and their pipes.