Zakarum Cathedral

The Zakarum Cathedral, otherwise referred to as the Westmarch Chapel, Church of the Holy Light or Church of the Holy Order is a Zakarum structure in Westmarch.

Reaper of Souls
During the Reapers' attack on the city, the cathedral was used as a place of sanctuary for refugees. However, the Reapers were able to gain entrance, killing many of those inside. Their deaths were avenged by the Nephalem.

In-game
The cathedral appears in Act V of Diablo III. This area must be explored in order to complete the achievement Ghost N Stuff.

Inside, one will find a Soul Crucible and Death Maiden Kasadya guarding it.

Once accessed during the quest, this area may not be revisited in Campaign Mode, but is open in Adventure Mode. Inside, there is a chance to find a Mysterious Chest containing God Butcher.