The Scarlet Monastery is one of the two new 5-man wings of the Scarlet Monastery in Mists of Pandaria, and is a combination of the former Cathedral and Graveyard wings of the Scarlet Monastery. It is designed for level 30–33 players, and features a level 90 heroic version as well.
The Crusade's fanatical leaders direct their followers from the Scarlet Cathedral, at the heart of the monastery grounds. This heavily guarded location functions as the order's headquarters, and some of the most zealous and intolerant crusaders roam the halls of this once-hallowed place.
Despite Scarlet Monastery Graveyard having been removed in patch 5.0.4 and merged into Scarlet Monastery, the old map, terrain, and objects were used in 2012's Hallow's End. The holiday's boss, Headless Horseman, exists in a special version of the dungeon in which its normal denizens are not present. Thus, it may be presumed that the use of the old dungeon simply was an oversight by Blizzard, as 2013's Hallow's End utilized the correct (i.e.: updated for Mists of Pandaria) dungeon.