The land around the temple was corrupted. Blisters and fissures erupted in oozes and slimes.
The entrance and walls of Ensellus War Barracks were lined with Hammarin Black Stone, who’s mortar was made from a form of Dark Vein pulled from a mine under the Temple of Apshai. It prevented mystical scrying and detection in many cases.
There is much concern across the realms if the Gwinnish forces ever try and reclaim the Sea King Empire that places such as these may become active again.