
Bastion
Metaphorical Use
When used metaphorically, 'bastion' implies strength, but also resistance to change. 
Cultural Connotation
In many cultures, 'bastion' is associated with historical institutions or ideals thought to be inflexible. 
Positive or Negative
Depending on the context, 'bastion' can have a positive spin (safety, security) or negative (rigidity). 