Crimson Wall

Crimson Walls are backing walls found in the Underground Crimson. These naturally occurring walls can be destroyed with a hammer, but will drop nothing. These walls do not stop enemies from spawning and cannot be used for proper housing. They will not spread the Crimson, however viewing the status with the dryad will consider this Crimson. so if you want a 0% Crimson World, you need to break these using an axe.