Montségur's solar alignment characteristics, visible on the morning of the summer solstice in particular, are part of what set this castle apart as an architectural wonder. This often mentioned solar phenomenon, occurring in an alignment of two windows in the fortress wall, has been observed by hundreds of students, astronomers, spiritual pilgrims and locals alike who come to the chateau specifically to view it every year and has been recorded and included in the documentary "The Otherworld," (by Richard Stanley) in 2013.