This is actually castle's interior - there's a wall on the left side of those walkways - but still half open upwards. Probably (very) uneven rock walls on the right side made it quite difficult to cover it completely with the roof - esp. with 16th century…
One of the darker sides of the castle - figuratively as well as literally. This "room" has no doors or windows. Nevertheless it's quite drafty, since there are large gaps between cave walls and castle roof. Still, almost…
There she weaves by night and day
A magic web with colours gay.
She has heard a whisper say,
A curse is on her if she stay
To look down to Camelot.
She knows not what the curse may be,
And so she weaveth steadily,
And little other care hath she,
When I entered this room and saw the walls panelled with wood in the same tone as the floor, lit with indirect light, it seemed like it was glowing from within. This, the near monochrome effect and the unusual sterile emptiness immediately reminded me of…