Another word I’ve seen before, but I didn’t really think of it as word (just as a meaningless Spanish-sounding name). In the wonderful Tintin books by Hergé, one of the recurring characters who appears in several stories is a General Alcazar who was constantly either overthrowing the government of his fictional Latin American country or being overthrown. Learning the definition gives it a bit more meaning and significance and I get the minor joke he was making.
A palace. Also: a fortress, a castle. Also fig.