Board Thread:Lore Discussion/@comment-189.107.213.230-20130725022718/@comment-10056803-20130725024930

Well, Bromjunaar may have been destroyed during the rebellion that ended the age of dragon rule and ejected Alduin to Skyrim in the titular game. Labyrinthian is apparently one of the oldest and most magical structures in Skyrim (At least partially due to Morokei holding the Staff of Magnus), rivaled only by the Eye of Magnus which was similarly blotting out the magical map, and said magic might have caused things like catastrophic spell malfunctions or natural disasters from abuse of certain shouts.

Also, Labyrinthian is OLD. It's been around since the reign of the dragons. Considering Bromjunaar is designed for use of the dragon priest masks, the sanctuary is definitely of similar age. Time, erosion, and weathering do wonders for destroying ancient structures in a land famed for its extreme weather.

The scholar came and died much more recently, considering Bromjunaar Sanctuary was already in ruins and the Wooden Mask was required to access it by that point.