It is said that a visit to Montsegur and specifically the climb to the Château gives everyone who undertakes it a special feeling. The feeling commences on the first sight of Château on the road from Foix.The old secret cathar routes are now signposted, well, at least where they cross the modern roads.
The rock itself is relatively slim so when in the Château there is no sense of being supported from below. For me the experience took the form of a very slight vertigo, but not at all unpleasant or threatening. It was as if I might be able to float. On many days there are clouds below the peak which makes the experience even more impressive.
Monsegur was the setting of the final defeat of the Cathars at the end of the Albigensian Crusade. Approaching it from the east it seems improbable that it ever could be captured, sat as it is, on top of its pillar of rock.
I had visited Monsegur during my first visit to the area, because in Rennes I had been told that one possible source for the treasure of Rennes was not the Visigothic treasure but Cathar treasure smuggled out during the last days of the siege.
On the day of the summer solstice the first rays of the sun pass directly through the arrow slits and out again through arrow slits on the other side
The windows are aligned to make this possible.
To observe this phenomenon it is necessary to climb Monsegur the previous the previous evening and camp on top of the mountain overnight.
Even on mid summers day it can be cold but the experience makes it worthwhile.
It is also pointed out that the ruined Château we see today is not the Cathar strongpoint which was finally captured and its occupants slaughtered in 1244. The Château was rebuilt after this event and so the alignment is not considered to have any significance for the cathar faith. However new buildings were often founded on previous buildings and the alignment may have been copied from the earlier structure