The main keep (tenshu) of the Japanese castle was usually used only for military purposes, so the floors were connected by steep stairs and the interior was built as one contiguous space, later divided in rooms and corridors with traditional Japanese room dividers (fusuma).
EXIF info:
Nikon Df
Lens: 24-70mm F/2.8G
Focal Length: 28mm
Aperture: F/11
Shutter Speed: 1/60s
ISO Sensitivity: ISO 4000