Coliseum of War (Hub 4)
It is a large religious complex, featuring a cleric's living abode, storage rooms, flooded catacombs, a bell tower and a large prayer hall. The Cathedral has been defiled and invaded by some of the strongest among Eidolon's minions.
Players will not be able to do much during their first visit to the Cathedral, although they can explore and discover a font of holy water.
A sheet of music will be necessary in order to play the organ and open new areas. There is a defiled holy relic in the main chamber, but if it is purified, it could be used to bless the altar once again. Only then will the Underhalls become accessible.